In 2024, ESET researchers found a number of malicious instruments within the techniques utilized by Kurdish and Iraqi authorities officers. The APT group behind the assaults is BladedFeline, an Iranian menace actor that has been energetic since no less than 2017, when it compromised officers throughout the Kurdistan Regional Authorities (KRG). This group develops malware for sustaining and increasing entry inside organizations in Iraq and the KRG. Whereas that is our first blogpost overlaying BladedFeline, we found the group in 2023, after it focused Kurdish diplomatic officers with the Shahmaran backdoor, and beforehand reported on its actions in ESET APT Exercise stories This autumn 2023-Q1 2024 and Q2 2024-Q3 2024.
The array of instruments utilized within the latest marketing campaign exhibits that since deploying Shahmaran, BladedFeline has continued to develop its arsenal. We discovered two reverse tunnels, a wide range of supplementary instruments, and most notably, a backdoor that we named Whisper and a malicious IIS module we dubbed PrimeCache. Whisper is a backdoor that logs right into a compromised webmail account on a Microsoft Change server and makes use of it to speak with the attackers through electronic mail attachments. PrimeCache additionally serves as a backdoor: it’s a malicious IIS module associated to what we known as Group 2 in our 2021 paper Anatomy of native IIS malware. Considerably, PrimeCache additionally bears similarities to the RDAT backdoor utilized by the Iran-aligned OilRig APT group.
Based mostly on these code similarities, in addition to on additional proof offered on this blogpost, we assess with medium confidence that BladedFeline is a subgroup of OilRig, an Iran-aligned APT group going after governments and companies within the Center East. We’ve beforehand reported on different exercise linked to OilRig. To keep away from confusion, we have now since refined our OilRig monitoring, and we now monitor each of these operations below a separate subgroup – Lyceum – inside OilRig.
BladedFeline has labored constantly to take care of illicit entry to Kurdish diplomatic officers, whereas concurrently exploiting a regional telecommunications supplier in Uzbekistan, and creating and sustaining entry to officers within the authorities of Iraq. This blogpost particulars the technical points of the preliminary implants delivered to BladedFeline’s targets, the hyperlinks between the victims, and lays the groundwork for associating this subgroup with OilRig.
Key factors of the blogpost:
BladedFeline compromised officers throughout the Kurdistan Regional Authorities no less than as early as 2017.
The preliminary implants used there may be traced again to OilRig.
We found BladedFeline after its operators compromised Kurdish diplomatic officers with the group’s Shahmaran signature backdoor in 2023.
This APT group has additionally infiltrated high-ranking officers throughout the authorities of Iraq.
We assess with medium confidence that BladedFeline is a subgroup inside OilRig.
We analyze two reverse tunnels (Laret and Pinar), a backdoor (Whisper), a malicious IIS module (PrimeCache), and varied supplementary instruments.
BladedFeline overview
BladedFeline is an Iran-aligned cyberespionage group, energetic since no less than 2017 in line with ESET telemetry. We found the group in 2023 when it deployed its Shahmaran backdoor in opposition to Kurdish diplomatic officers. Shahmaran, named after a legendary half-snake, half-woman creature from Iranian folklore, is a 64-bit moveable executable that we discovered within the goal’s Startup listing. This straightforward backdoor doesn’t use any compression or encryption for community communications. After checking in with the C&C server, the backdoor executes any operator instructions supplied, which embrace importing and downloading further recordsdata, requesting particular file attributes and offering file and listing manipulation API.
As evidenced by the marketing campaign toolset we describe on this blogpost; since deploying Shahmaran, BladedFeline has continued to develop its malware with a view to retain and even additional prolong its entry to the KRG and to excessive ranges throughout the authorities of Iraq (GOI). We uncovered the marketing campaign in 2024 after discovering BladedFeline’s Whisper backdoor, PrimeCache IIS backdoor, and a set of post-compromise instruments within the networks of Kurdish diplomatic officers, Iraqi authorities officers, and a regional telecommunications supplier in Uzbekistan.
We detected and picked up one model of Whisper and located one other on VirusTotal, uploaded by a consumer in Iraq. They’re nearly similar, and we had been in a position to decide the seemingly id of the VirusTotal uploader, based mostly on information within the Whisper pattern and different samples uploaded below the identical submitter ID. PrimeCache, Flog (a webshell), and Hawking Listener (an early-stage implant that listens on a specified port) had been all uploaded to VirusTotal by the identical submitter ID who uploaded the Whisper samples. Based mostly on the Whisper hyperlink and the shut timeframe (each had been uploaded inside a matter of minutes) we consider it was deployed by BladedFeline to a sufferer in Iraq’s authorities. A number of the instruments talked about beneath within the Timeline are mentioned later within the report (e.g., Slippery Snakelet).
Timeline
2017-09-21 ● VideoSRV reverse shell on KRG system
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2018-01-30 ● RDAT backdoor on KRG system
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2019-07-09 ● Customized Plink on KRG system
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2021-05-01 ● Sheep Tunneler on KRG system
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2023-01-23 ● LSASS dumped on KRG system
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2023-02-01 ● Shahmaran backdoor on KRG system
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2023-03-25 ● First sufferer focused at a telecommunications firm in Uzbekistan
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2023-06-12 ● Shahmaran model 2 on KRG system for entry upkeep
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2023-12-14 ● BladedFeline operators executing CLI instructions on KRG system
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2023-12-16 ● Slippery Snakelet backdoor on KRG system
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2023-12-20 ● P.S. Olala (a PowerShell executor) on KRG system
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2023-12-20 ● PsExec on KRG system
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2024-01-07 ● Whisper backdoor on KRG system
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2024-02-01 ● Laret reverse tunnel on KRG system
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2024-02-20 ● Pinar reverse tunnel on KRG system
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2024-02-29 ● PrimeCache malicious IIS module uploaded to VirusTotal
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2024-03-11 ● Whisper model 2, Flog, and Hawking Listener uploaded to VirusTotal
Attribution
Our attribution of this marketing campaign to BladedFeline is predicated on the next:
The marketing campaign targets members of the KRG, as have earlier assaults performed by BladedFeline.
The unique assault exercise concentrating on the KRG group allowed us to determine successive malware, as BladedFeline has tried to take care of and broaden entry to the group.
Additional evaluation of the assaults led us to determine the telecommunications sufferer in Uzbekistan.
On the similar time, wanting into the Whisper backdoor helped us determine the GOI sufferer.
We assess that BladedFeline is concentrating on the KRG and the GOI for cyberespionage functions, with a watch towards sustaining strategic entry to high-ranking officers in each governmental entities. The KRG’s diplomatic relationship with Western nations, coupled with the oil reserves within the Kurdistan area, makes it an attractive goal for Iran-aligned menace actors to spy on and doubtlessly manipulate. In Iraq, these menace actors are likely making an attempt to counter the affect of Western governments following the US invasion and occupation of the nation.
We consider with medium confidence that BladedFeline is a subgroup of OilRig:
As does OilRig, BladedFeline targets organizations within the Center East with the aim of cyberespionage.
We’ve discovered OilRig instruments (VideoSRV and RDAT) in a compromised KRG system.
BladedFeline’s malicious IIS module PrimeCache shares code similarities with OilRig’s RDAT.
BladedFeline shouldn’t be the one subgroup of OilRig that we’re monitoring: we have now already been monitoring Lyceum, also called HEXANE or Storm-0133, as one other OilRig subgroup. Lyceum focuses on concentrating on varied Israeli organizations, together with governmental and native governmental entities and organizations in healthcare. Main instruments we attribute to Lyceum embrace DanBot, the Shark, Milan, and Marlin backdoors, Photo voltaic and Mango, OilForceGTX, and a wide range of downloaders utilizing legit cloud companies for C&C communication.
We’ll proceed to make use of the identify OilRig to consult with the mother or father group, also called APT34 or Hazel Sandstorm (previously EUROPIUM). OilRig is a cyberespionage group that has been energetic since no less than 2014 and is usually believed to be based mostly in Iran. The group targets Center Japanese governments and a wide range of enterprise verticals, together with chemical, vitality, finance, and telecommunications. Notable OilRig campaigns embrace the 2018 and 2019 DNSpionage marketing campaign, concentrating on victims in Lebanon and the United Arab Emirates; the 2019–2020 HardPass marketing campaign, utilizing LinkedIn to focus on Center Japanese victims within the vitality and authorities sectors; the 2020 assault in opposition to a telecommunications group within the Center East utilizing the RDAT backdoor; and the 2023 assaults concentrating on organizations within the Center East with the PowerExchange and MrPerfectionManager backdoors.
OilRig instruments utilized by BladedFeline
We’ve discovered two OilRig instruments on the KRG machines compromised by BladedFeline.
RDAT
We found a beforehand unreported model of the OilRig backdoor RDAT on two KRG sufferer techniques. Analyzing RDAT, we discovered that the operational circulate (see Unit 42’s report for specifics), compilation timestamp (2017-12-26 10:49:35), and file write time (2018-01-30) align with OilRig exercise and concentrating on, notably with regard to the group’s 2017 exercise. We noticed a file with an SHA-1 of 562E1678EC8FDC1D83A3F73EB511A6DDA08F3B3D and a path of C:WindowsSystem32LogonUl.exe on each techniques. The PDB path additionally corroborates that this binary is RDAT: C:UsersVoidDesktopRDATclientx64Releaseclient.pdb. Thus far, we have now solely ever noticed RDAT in use by OilRig. Furthermore, we have now not seen any customized implant sharing between OilRig and different Center Japanese teams, and it seldom happens between Iran-aligned menace actors.
Additional bolstering the case that BladedFeline is an OilRig subgroup, as with Lyceum, is the evaluation linking RDAT with PrimeCache, a malicious IIS module that was uploaded to VirusTotal presumably by the GOI sufferer. This hyperlink is explored in additional depth within the Hyperlinks with OilRig part of the blogpost.
VideoSRV
One further information level on the OilRig and BladedFeline connection is a reverse shell deployed to one of many KRG victims (September twenty first, 2017) previous to RDAT getting dropped on the identical system (January thirtieth, 2018). VideoSRV (SHA-1: BE0AD25B7B48347984908175404996531CFD74B7), so named for its filename videosrv.exe, has the PDB string C:Usersv0idDesktopreverseShellclientProxyx64ReleaseConsoleApplication1.pdb, which bears some similarities to the RDAT PDB string C:UsersVoidDesktopRDATclientx64Releaseclient.pdb.
Technical evaluation
Preliminary entry
It’s nonetheless unclear how BladedFeline is creating entry to its victims. What we all know is that within the case of the KRG victims, the menace actors obtained entry no less than way back to 2017 and have maintained it ever since. As for the GOI victims, we suspect that the group exploited a vulnerability in an utility on an internet-facing internet server, which allowed them to deploy the Flog webshell.
Toolset
PrimeCache – malicious IIS module
PrimeCache, whose identify we derived from the RTTI AVRSAPrimeSelector and its filename (cachehttp.dll), is a passive backdoor applied as a local IIS module with an inner identify of HttpModule.dll. It was uploaded to VirusTotal by the identical consumer who uploaded one of many Whisper backdoor samples. It’s a 64-bit C++ DLL with a compilation timestamp of 2023-05-14 06:55:52 and has a minimized PDB string of simply HttpModule.pdb. It has a single export: RegisterModule.
PrimeCache is a successor to a group of unattributed IIS backdoors that we have now beforehand reported as Group 2 (easy IIS backdoors) in our 2021 blogpost, Anatomy of native IIS malware. We obtained these authentic samples from VirusTotal the place they had been uploaded by customers from Bahrain, Israel, and Pakistan, between 2018 and 2020. Based mostly solely on the situation of the presumed victims, it’s potential that these instances had been additionally associated to BladedFeline – or, extra broadly, OilRig – actions.
Predominant performance
PrimeCache’s predominant performance is applied within the CGlobalModule::OnGlobalPreBeginRequest handler. This can be a distinctive implementation, differing from its predecessors, which used the CHttpModule::OnBeginRequest handler. PrimeCache filters incoming HTTP requests, solely processing these from the BladedFeline operators, that are acknowledged by having a cookie header with the construction:
F=<command_ID>,<param>;
Be aware that this worth may be standalone or embedded into an extended cookie, surrounded by semicolon (;) characters.
The backdoor works in an uncommon method (new with this model as in contrast with our 2021 evaluation). Relatively than accepting a backdoor command and all its parameters inside a single HTTP request, every motion is cut up into a number of requests. First, the BladedFeline operator sends a person request for every single parameter; these parameters are saved in a world construction. Then the operator sends one other request to set off the backdoor command. Lastly, PrimeCache makes use of the beforehand acquired parameters to execute the desired motion, after which clears the cached parameters.
Operator instructions
There are three forms of requests that may be acquired by the backdoor, as proven in Desk 1.
Desk 1. PrimeCache operator instructions
<command_ID>
Parameter
Description
1
Format: <key>=<worth>
Clears the checklist of beforehand saved parameters and provides the brand new worth. Most parameters are encrypted; see Encryption beneath.
0
Not used.
Triggers the backdoor motion, utilizing beforehand transmitted backdoor parameters.
Different
Format: <key>=<worth>
Provides the desired worth to the checklist of saved parameters (doesn’t clear the checklist). Most parameters are encrypted; see Encryption beneath.
As soon as the motion is triggered (through <command_ID>=0), PrimeCache performs an motion, based mostly on the beforehand obtained parameters, as proven in Desk 2. One be aware on the chart beneath:
The PrimeCache motion is operator command (OpCom) a, the session key’s OpCom ok, binary information is OpCom b, and the filename is OpCom f.
Desk 2. PrimeCache post-operator command actions
PrimeCache motion
Session key
Binary information
Filename
Command description
Return worth
r
RSA-encrypted session key
AES-encrypted command line
Null
Runs the desired command through popen.
Command output
r2
Runs the desired command through CreateProcessW.
r3
(Presumably) runs the desired command by sending it to a different (unknown) course of through the named pipe .pipeiis, then reads (presumably) the command output from the identical pipe.
u
AES-encrypted file content material
Native filename
Creates an area file with the desired identify and content material.
OK
d
Null
Exfiltrates the given file from the compromised IIS server.
File content material
Encryption
Just like its predecessors, PrimeCache makes use of each RSA and AES-CBC for its C&C communication. The parameters and the return values are all the time AES-CBC encrypted utilizing the session key, then base64 encoded. The session key’s RSA encrypted; the backdoor has a hardcoded non-public and public RSA key (not a pair) to deal with each instructions of the communication.
A statically linked Crypto++ library is used to deal with the encryption and decryption operations.
C&C communications
Operator instructions are transmitted within the cookie header (one other deviation from earlier variations, which used the URL or the HTTP request physique). PrimeCache responses are added to the HTTP response physique. If a file is being exfiltrated, the Content material-Sort header is about to attachment, matching the performance of the earlier variations.
The PrimeCache predecessors additionally used the identical encryption scheme, and comparable parameter names (a, c, f, ok), however all had been despatched to the backdoor in a single request. The one supported instructions had been r, u, and d.
Hyperlinks with OilRig
Once we examine PrimeCache with RDAT, as described within the RDAT attribution subsection, we see a number of similarities that assist our supposition that BladedFeline is a subgroup of OilRig.
Each RDAT and PrimeCache use the Crypto++ library, and each parse the backdoor instructions utilizing the common expression [^,]+.
The payload makes an attempt to parse the decrypted cleartext utilizing the common expression [^,]+ to get the command worth and the command arguments which might be cut up with a comma.
Each share a operate, proven in Determine 1, that executes a shell command and reads the output, which, throughout our corpus, is discovered solely in these two items of malware.
Determine 1. A singular operate to execute a shell command, shared between RDAT (left) and PrimeCache backdoors (proper)
Whisper backdoor
Whisper is a 32-bit Home windows binary written in C#/.NET, named after its PDB strings G:csharpWhisper_Trojan_winformWhisper_Trojan_winformWhisper_Trojan_winformobjReleaseVeaty.pdb and Z:csharpWhisper_Trojan_winform_for_releaseWhisper_Trojan_winformWhisper_Trojan_winformobjReleaseVeaty.pdb. It makes use of a Microsoft Change server to speak with the attackers by sending electronic mail attachments through a compromised webmail account. We’ve seen two variations of the backdoor: we detected and picked up one model, and was uploaded to VirusTotal from Iraq. These samples are nearly similar, however we had been in a position to decide the seemingly id of the VirusTotal uploader based mostly on information within the Whisper pattern and different samples uploaded by that consumer.
Each these variations of Whisper have timestomped compilation timestamps (2090-04-11 23:38:14 and 2080-12-11 03:50:47). They’re constructed utilizing Costura, presumably to make sure that the sufferer’s system makes use of the DLLs packaged with the binary and never DLLs within the International Meeting Cache.
Whisper’s operation shouldn’t be the primary time we have now noticed an OilRig subgroup utilizing cloud companies for its C&C protocol. Whereas, in contrast to with Whisper, there have been no emails really being despatched, Lyceum used electronic mail drafts for communication between its malware and operators all through 2022, as we described in a earlier blogpost.
Operational workflow
Whisper doesn’t require or settle for any arguments. As an alternative, its dropper – which we dubbed Whisper Protocol after its filename, Protocol.pdf.exe – writes its configuration file to disk alongside it (see the Whisper Protocol part). The config file, proven in Determine 2, is in XML format with its key and worth strings base64 encoded. It’s known as by the Specs class of Whisper, which makes use of a operate – DelockItems – to base64 decode the config variables.
Determine 2. Whisper configuration file with its base64-encoded parts (left) and decoded (proper)
Determine 3 exhibits the operational circulate of Whisper, which we element within the following paragraphs.
Determine 3. Fundamental operational circulate of Whisper
Whisper’s operational circulate may be damaged down into seven steps:
In Step 1, Whisper makes use of the credentials from the config file (line 15 in Determine 2) and the Microsoft Change Net Companies class ExchangeService to aim to log into compromised webmail accounts. As soon as Whisper efficiently logs into an account, it saves the credentials in reminiscence and writes the next to the log file c:WindowsTempWindowsEventLogs.txt:
———— ItemContext is about: username [<username>] , use_defaultCred: [credentials>]
If no credentials within the config file are legitimate, Whisper logs the next error messages to the log file:
———————————- there was No Solution to entry any MailBox.
__________ Extraction operate known as.
If an sudden error is caught, Whisper writes the next to the log file (be aware the misspelling of the phrase occurred, indicative of a non-native English speaker) and exits utilizing the Atmosphere.Exit(Int32) methodology. Surprisingly, the exitCode used, 0, signifies that the method accomplished efficiently.
———————————-__ an unknown Exception happend. program turned off
Subsequent, in Step 2, Whisper makes use of the credentials from the earlier step to test for inbox guidelines utilizing the ExchangeService.GetInboxRules methodology (which [r]etrieves a group of Inbox guidelines which might be related to the desired consumer). Utilizing the worth in line 13 of the configuration file (key=”receive_sign”, worth=”PMO”), Whisper iterates over the inbox guidelines in search of that worth to be laid out in considered one of three locations: topic, physique, or subjectorbody and for emails matching that worth to be despatched to a specified location (deleteditems or inbox, relying on the model of Whisper). If the inbox has such a rule, Whisper goes to the following step; in any other case, Whisper creates a rule with the given parameters:
Rule identify: MicosoftDefaultRules.
Transfer to folder: deleteditems or inbox.
One model of Whisper specifies the deleteditems folder; the opposite factors to the inbox. Each are hardcoded within the separate binaries.
Mark as learn: true.
Situation: topic accommodates PMO.
The situation to search for the string, topic, is hardcoded in each variations of Whisper. The string to search for, PMO, is within the configuration file utilized by Whisper; we had been unable to gather the opposite configuration file.
In Step 3, Whisper initiates a endless do loop that sends a check-in electronic mail message from the compromised electronic mail account in Step 1 to an electronic mail deal with specified within the configuration file (line 16, key=”alive_mail”). The check-in message is shipped each 10 hours (line 10 within the configuration file, key=”al_time”; in minutes), the topic (line 17, key=”alive_msg_subj”) is Content material, and the message physique accommodates the string outlined beneath:
“Content material ID: ” + base64_encode(“COMPUTERNAME:USERDNSDOMAIN:USERNAME”)
Subsequent, in Step 4, Whisper fetches operator instructions. It does so by looking out the inbox recognized in Step 1 for recordsdata in a given folder (deleteditems or inbox, relying on the model of Whisper) with attachments the place the topic matches a string (equipped within the configuration file; PMO in the one configuration file we collected). For matching emails with attachments, Whisper scrapes the attachment physique (which ought to include encrypted instructions) and shops the sender’s electronic mail deal with to be used later because the C&C server to which operator command outcomes are uploaded.
In Step 5, Whisper decrypts the operator instructions. It does so by first base64 decoding the string containing the command after which decrypting the outcome utilizing the .NET AES class with a 16-byte initialization vector and the encryption key discovered within the configuration file (line 18, key=”enc_key” worth=”cXdlcmFzZHp4Y3ZmZ2d0aGhsZGZvZ2g/bHZtZ2xrZyE=”). Decrypted instructions are within the type of <cmd_id>;<command_to_execute>. The command ID, instructions, and command output are saved within the following format:
base64-encoded(<command_id>: <cmd_id>n<cmd_output>n)
Then, in Step 6, Whisper executes the backdoor instructions and data the outcomes. Attainable instructions embrace:
The info written to disk is:
that is my file content material
<filepath>
<filename>
<nbytes-to-write>
The bytes to write down are base64 encoded (and decoded earlier than writing to disk). Profitable execution returns:
file acquired correctly. wrote to: <filepath><filename>
Ship a file to the C&C server
This command is prefixed with that is my required file path adopted by n<unknown_variable>n<filepath><filename>. Whisper reads the contents of the file into reminiscence, base64 encodes them, and returns:
that is my required file <path>n<unknown_variable>n<filename>n<base64_encoded_file_contents>
Execute a PowerShell script
This command doesn’t have a prefix and as an alternative solely accommodates a plaintext command that PowerShell is able to executing, postfixed with a pipe after which Whisper appends Out-String. Output is saved on this kind:
base64-encoded(<command_id>: <cmd_id>n<cmd_output>n)
Lastly, in Step 7, Whisper sends the command output in an electronic mail message to the C&C inbox present in Step 4. The e-mail is formatted with these particulars:
sending electronic mail deal with: inbox from Step 1,
recipient: electronic mail deal with from Step 4,
topic: Electronic mail (from the configuration file, line 14, key=”send_sign”),
message physique: Hey There! discover your leads to the attachment (hardcoded within the binary), and
attachment: output from the instructions in Step 6, encrypted with the identical encryption key in Step 5 (configuration file line 18, key=”enc_key” worth=”cXdlcmFzZHp4Y3ZmZ2d0aGhsZGZvZ2g/bHZtZ2xrZyE=”).
Steps 4–7 proceed in a loop utilizing the identical check-in schedule from Step 3 till the credentials hardcoded within the configuration file are modified.
Shahmaran backdoor
The Shahmaran backdoor, named after a legendary half-snake, half-woman creature from Iranian folklore, is a 64-bit PE that was discovered within the startup folder as:
%ROAMINGAPPDATApercentMicrosoftWindowsStart MenuProgramsStartupadobeupdater.exe
At system startup, Shahmaran creates a Home windows occasion object, SysPrep. It’s potential that the Shahmaran builders selected SysPrep because the occasion identify to mix into the background noise, as SysPrep is a part of the Home windows imaging course of. Home windows admins use it to create a normal Home windows picture (sometimes called a Gold or Golden picture) earlier than deployment to enterprise techniques. Determine 4 exhibits the SysPrep occasion object on a compromised system as seen by Sysinternals’ WinObj.
Determine 4. Sysinternals’ WinObj displaying the SysPrep occasion object on a compromised system
The C&C area is hardcoded, olinpa[.]com, as is the port, 80, and the Consumer-Agent string, of which there are two. The preliminary connection to the C&C makes use of an incomplete Consumer-Agent string (it’s lacking the closing parenthesis):
Mozilla/4.0 (suitable; MSIE 6.0; Home windows NT 5.0
Subsequent communication with the C&C makes use of the corrected Consumer-Agent string:
Mozilla/4.0 (suitable; MSIE 6.0; Home windows NT 5.0)
Shahmaran doesn’t use any compression or encryption for community communications. And whereas the port is hardcoded (80), there are code fragments that test for the port in use and replace communication variables if port 443 is used.
After checking in with the C&C server, Shahmaran executes any operator instructions supplied, returns any output from these instructions, then sleeps for 30 seconds earlier than checking in with the C&C server once more, advert infinitum. Desk 3 exhibits the obtainable operator instructions and their capabilities.
Desk 3. Operator instructions and their descriptions
Operator command
Description
1 <path/filename>
Returns the datetime that the desired file was written to disk in UTC, prepended with id= and within the format YYYY/MM/DD HH:MM:SS.
2 <filename> <supply> <vacation spot>
Strikes the desired file to the desired location. Returns the output of the file transfer operation prepended with id=.
3 <path/filename>
Deletes the desired file. Returns the output of the file delete operation prepended with id=.
4 <path/listing>
Creates the desired listing. Returns the output of the listing creation operation prepended with id=.
5
Creates a log file within the hardcoded location c:programdata~tmp.log, if it doesn’t exist already.If the file already exists, reads the contents and returns them to the C&C server with the file’s timestamp in UTC and within the format YYYY/MM/DD HH:MM:SS, then deletes the file.If the file doesn’t exist, returns the filename and path.If an error happens, returns the error.All returned information is prepended with s=.
6 <path/filename> <information>
Checks for the desired file. If discovered, writes the supplied information to the file and returns s=<provided_filename>. If not discovered, returns u=<error_code>.
7 <path/filename>
Creates the desired file. Returns s= appended with both the filename (success) or an error code.
8 <path/filename>
Checks for the presence of the desired filename in a compressed folder within the specified location on disk and creates it if it doesn’t exist. Returns s= appended with the filename and the timestamp in UTC within the format YYYY/MM/DD HH:MM:SS. The timestamp is used to find out whether or not the file was already current or was simply created.
After executing an operator command, Shahmaran sends the output to the C&C server utilizing the format t=<operator_command>&<command_output>, comparable to t=1&s=<file_timestamp>.
Slippery Snakelet backdoor
Slippery Snakelet is a small Python-based backdoor with restricted capabilities:
1. executes a command through cmd.exe,
2. downloads a file from a URL, and
3. add a file to the /newfile/ URI path.
Slippery Snakelet has a hardcoded C&C server, zaincell[.]retailer, and communicates with it through URLs of the shape https://zaincell[.]retailer/request/<UID>, the place the <UID> is the sufferer’s login area and the compromised laptop’s identify separated by a interval then base64 encoded (e.g., victim_domain.computer_name = dmljdGltX2RvbWFpbi5jb21wdXRlcl9uYW1l).
Slippery Snakelet additionally has this hardcoded Consumer-Agent:
Mozilla/5.0 (Home windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.104 Safari/537.36
The C&C server was disguised as an Arabian Gulf E-Studying website and the default HTML touchdown web page doesn’t include any instructions. When Slippery Snakelet provides a accurately formatted request (e.g., https://zaincell[.]retailer/request/<UID>), the C&C server inserts <code> tags comparable to <code>6wjTyB3Y20KSzU1VUlTagp3aG9hbWkKbnVsbApudWxs</code> into the web page, and Slippery Snakelet collects and decodes these.
Slippery Snakelet base64 decodes every thing from the eighth character to the top of the string (i.e., Y20KSzU1VUlTagp3aG9hbWkKbnVsbApudWxs within the instance above). The decoded output is newline separated and accommodates the 5 gadgets described in Desk 4
Desk 4. Slippery Snakelet arguments and choices
Instructions
Choices
Instance
Command Sort
cm (execute cmd.exe command)getfl (obtain a file)sendfl (add a file)
cm
Command ID
CMID (a random string)
K55UISj
Command | FileUrl | FilePath
Respectively for cm | getfl | sendfl
whoami
Null | SavePath | FilePath
Respectively for cm | getfl | sendfl
null
Null
Unknown
null
Laret and Pinar – reverse tunnels
Laret and Pinar, whose names are derived from the interior names in every respective file, are 32-bit Home windows binaries written in C#/.NET. Each have timestomped PE compilation timestamps – a tactic that’s widespread amongst Center Japanese (and notably Iran-nexus) menace teams – of 2058-02-07 00:12:48 and 2072-07-10 18:26:15, respectively. Each had been discovered on two techniques on the places in Desk 5.
Desk 5. Areas of Laret and Pinar on disk, together with filenames
Reverse tunnel
Location
Laret
%APPDATApercentLocalLEAP DesktopLEAPForm.exe
<unknown_location>wincapsrv.exe
Pinar
C:Program FilesLEAP OfficeSystemMain.exe
C:Program FilesLEAP Officewinhttpproxy.exe
Within the case the place we should not have a location on disk for Laret however we do have the filename (wincapsrv.exe), we might see that Laret was downloaded from http://178.209.51[.]61:8000/wincapsrv.exe through PowerShell. Sadly, we didn’t handle to find the place it was written to disk. Makes an attempt to enumerate the IP and obtain the file had been rebuffed by the C&C server, seemingly indicating that some type of compromised host identification is required within the connection setup (which we should not have).
Relating to writing to disk, BladedFeline operators seemingly timestomped the file creation date of Pinar to 2017-09-14 14:56:00 on one of many two compromised techniques. How the file creation date was timestomped is an open query, however it exhibits that the attackers have compromised these two techniques to such an extent that they in all probability have administrative rights.
At runtime, each Laret and Pinar depend on a configuration file in the identical listing as their binaries for eight required variables, that are listed in Desk 6.
Desk 6. Laret and Pinar configuration parameters with default hardcoded values
Subject
Description
Default worth
ssh_host
C&C IP deal with.
N/A
ssh_port
22
ssh_username
C&C username.
N/A
ssh_pass
C&C password.
N/A
local_port
9666
process_file
File to execute earlier than executing any reverse tunnel actions.
N/A
wait_time_minutes
Time to attend between check-ins with the C&C server.
10f (271)
remote_port
Port quantity used for port forwarding.
1234
We’ve up to now not collected the configuration file however have reconstructed its seemingly content material, present in Determine 5, based mostly on code evaluation. Studying from the configuration file is finished by base64 decoding the encoded string to bytes, which leads to strings of space-delimited, hexadecimal-encoded character values, which in flip are decoded into ASCII strings.
Determine 5. Instance contents of the configuration file utilized by Laret and Pinar reverse tunnels
The BladedFeline builders consult with this as Delocking and the alternative (writing to the configuration file) as Enlocking. This in all probability signifies a passing familiarity with English, however the builders had been removed from proficient. Different examples of weak translation expertise embrace:
time Alapsed and shopper not linked
aerpoo after
Ready connection …
error in creaate ssh shopper
Curiously, at one other level within the reverse tunnels, the builders accurately spelled the phrase elapsed (time elapsed!), which is indicative of poor coding and lax code evaluate, if any is carried out (e.g., there may be loads of command outcome textual content output to the command line, as if the reverse tunnels had been shipped instantly after profitable testing was accomplished).
The precise operate and circulate of Laret and Pinar after accumulating the parameters from the configuration file is sort of banal, however that’s in all probability an intentional effort to mix in. Each search for a filename within the process_file parameter and, if a file matching the equipped identify is current, execute it and begin two threads:
Units up an SSH connection to the C&C IP within the configuration file utilizing the Core.Renci.SshNet DLL included throughout the binary. Port 22 is hardcoded because the C&C port and port forwarding can be enabled, utilizing the remote_port variable from the configuration file.
Units up a listener on the port specified within the local_port parameter of the configuration file. Be aware that any information despatched to the listener is finished within the clear (i.e., no encryption or obfuscation is used past additional characters which might be eliminated on the time of receipt by Laret and Pinar).
If no file is laid out in process_file, each Laret and Pinar skip establishing a listener port.
Laret and Pinar solely differ considerably in that Pinar units up a service, known as Service1, for persistence previous to executing the 2 threads. Laret has no technique of persistence past its course of working indefinitely.
Supplementary instruments
Flog webshell
Flog is a webshell discovered uploaded to VirusTotal from Iraq by the identical submitter who uploaded one of many variations of Whisper. Based mostly on that and the shut timeframe (each had been uploaded inside a matter of minutes) we consider it was deployed by BladedFeline to the sufferer within the Iraq authorities.
Flog, so named for its filename – flogon.aspx – appears for particular enter from the BladedFeline operators of the shape <password>=<(a|b|c|d)>#<path>
Flog hashes the password, which should match the MD5 checksum 4CC88CE123B0DA8D75C0FE66A39339F6.
Variables (a|b|c|d) are command choices:
a returns, for the trail supplied, a listing itemizing and the byte size of every file,
b creates a file on disk, utilizing the trail supplied,
c splits the trail variable on a pipe and writes a file to disk the place the primary a part of the trail is the filename and the second half is the information to write down, and
d deletes a specified file given within the equipped path.
Hawking Listener
Hawking Listener, so named for its PDB string – C:Usersg18u04sourcereposHawkingHawkingobjReleaselistner.pdb – is a 32-bit .NET/C# Home windows binary with a timestomped compilation time of 2057-11-14 16:59:12. It was additionally uploaded to VirusTotal by the identical consumer who uploaded Flog and might be a BladedFeline instrument. It implements the .NET HTTPListener class to arrange a listener with a hardcoded URL (which we can’t disclose on this case with out revealing the id of the sufferer). Alternatively, Hawking may be supplied at runtime with URLs for the listener socket to watch.
Hawking listens for a supplied QueryString (from a BladedFeline operator) with snmflwkejrhgsey as the important thing within the key-value pair. As soon as acquired, Hawking executes the worth in cmd.exe and returns the output. To cease Hawking, operators want solely ship cease as the important thing within the QueryString with a non-null variable within the worth.
Hawking logs all interactions, runtime arguments, and command output to the file log.txt in its working listing.
P.S. Olala
P.S. Olala is a 32-bit .NET binary named for its supposed operate (executing PowerShell scripts) and its PDB path G:csharppsExecuterServiceewsServiceobjReleaseOlala.pdb. It doesn’t settle for any runtime arguments. Relatively, at runtime, P.S. Olala makes use of the Run(ServiceBase[]) methodology of the .NET ServiceBase class to register itself as a service with the Service Management Supervisor (for persistence).
When the P.S. Olala service known as, it spawns a thread and executes the operate mainLoop, proven in Determine 6. Basically, P.S. Olala is an executor of the PowerShell script saved in %APPDATApercentLocalMicrosoftInputPersonalizationTrainedDataStore.ps1.
Determine 6. The primary operate of P.S. Olala
Sadly, we had been unable to gather any of the TrainedDataStore.ps1 scripts. Nevertheless, contextual data signifies it’s seemingly an executor of the Whisper backdoor, or one of many reverse tunnels (Laret or Pinar). Your entire circulate (P.S. Olala → TrainedDataStore → Whisper/Laret/Pinar) might be an elongated persistence chain aiming to take care of entry.
Sheep Tunneler
Sheep Tunneler, a customized tunneling utility that we named based mostly on the PDB string C:UserssheepsourcereposMPMPobjReleaseMP.pdb), has been noticed within the two following places:
%APPDATApercentLocalMicrosoftWindowsRingtonesRingService.exe
%APPDATApercentLocalMicrosoftWindowsShellmspsrv.exe
Sheep Tunneler may be executed in two modes: community tunneling (through the use of the runtime argument center) or join again (through the use of the arguments cb <ip>:<port>).
Whisper Protocol
Whisper Protocol, so named for its filename (Protocol.pdf.exe) is a 64-bit Python-compiled Home windows binary with a compilation timestamp of 2024-03-11 09:01:20. It creates a folder in C:ProgramDataVeeamUpdate and writes each Whisper and its configuration file to that folder. Whisper Protocol additionally copies itself to %APPDATApercentRoamingMicrosoftWindowsStart MenuProgramsStartupVeeamUpdate.lnk for persistence. Lastly, it executes Whisper and exits gracefully.
Conclusion
BladedFeline is a complicated menace group that focuses on concentrating on Iraqi and Kurdish victims, particularly governmental officers and organizations. We assess that the group is probably going a subgroup of OilRig. We anticipate finding that BladedFeline will stick with implant improvement with a view to keep and broaden entry inside its compromised sufferer set, seemingly for cyberespionage.
For any inquiries about our analysis revealed on WeLiveSecurity, please contact us at threatintel@eset.com.
ESET Analysis provides non-public APT intelligence stories and information feeds. For any inquiries about this service, go to the ESET Menace Intelligence web page.
IoCs
Information
SHA-1
Filename
Detection
Description
01B99FF47EC6394753F9CCDD2D43B3E804F9EE36
Avamer.pdf.exe
Python/TrojanDropper.Agent.GI
Python-compiled dropper for Spearal
1C757ACCBC2755E83E530DDA11B3F81007325E67
Win_Updates.exe
MSIL/Agent.EUM
Spearal, a BladedFeline backdoor.
272CF34E8DB2078A3170CF0E54255D89785E3C50
scr8B45.ps1
PowerShell/TrojanDropper.Agent.AJU
PowerShell script to put in Spearal.
37859E94086EC47B3665328E9C9BAF665CB869F6
ncms_demo.msi
MSIL/Agent.EUM
MSI contained in the zip archive that drops and executes a PowerShell script that in flip drops and executes Spearal.
3D21E1C9DFBA38EC6997AE6E426DF9291F89762A
flogon.aspx
ASP/Agent.BI
Flog webshell.
4954E8ACE23B48EC55F1FF3A47033351E9FA2D6C
winsmsrv.exe
MSIL/HackTool.Agent.YN
Pinar, a reverse tunnel.
562E1678EC8FDC1D83A3F73EB511A6DDA08F3B3D
LogonUl.exe
Win64/OilRig_AGen.A
RDAT backdoor.
66BD8DB40F4169C7F0FCA3D5D15C978EFE143CF8
Protocol.pdf.exe
Python/TrojanDropper.Agent.FT
Whisper Protocol, the dropper that writes and executes the Whisper backdoor.
6973D3FF8852A3292380B07858D43D0B80C0616E
VeeamUpdate.exe
MSIL/Agent.ERR
Whisper backdoor.
73D0FAA475C6E489B2C5C95BB51DEDE4719D199E
winhttpproxy.exe
MSIL/HackTool.Agent.XY
Pinar, a reverse tunnel.
B8AFC21EF2AA854896B97F1C81B376DCDDE2466D
RunExeActionAllowedList.exe
MSIL/Agent.ERR
Whisper backdoor.
BB4FFCDBFAD40125080C13FA4917A1E836A8D101
MFTD.exe
MSIL/Tiny.GL
Hawking Listener.
BE0AD25B7B48347984908175404996531CFD74B7
videosrv.exe
Generik.BKYYERR
VideoSRV, a reverse shell.
E8E6E6AFEF3F574C1F5228BDB28ABB34F8A0D09A
wincapsrv.exe
MSIL/HackTool.Agent.XY
Laret, a reverse tunnel.
F28D8C5C2283019E6ED788D20240ABC8554CADB5
N/A
MSIL/Agent.EUM
Zip archive that accommodates an MSI that drops and executes a PowerShell script that in flip drops and executes Spearal.
Community
IP
Area
Internet hosting supplier
First seen
Particulars
178.209.51[.]61
N/A
9 Web Options AG
2023‑12‑18
Distribution server for BladedFeline’s Laret reverse tunnel.
185.76.78[.]177
N/A
EDIS GmbH – Noc Engineer
N/A
C&C utilized by Spearal.
MITRE ATT&CK methods
This desk was constructed utilizing model 17 of the MITRE ATT&CK framework.
Tactic
ID
Title
Description
Reconnaissance
T1595.002
Lively Scanning: Vulnerability Scanning
BladedFeline in all probability conducts vulnerability scanning in opposition to targets to determine doubtlessly weak, uncovered purposes.
Useful resource Growth
T1583.001
Purchase Infrastructure: Domains
BladedFeline registers domains to make use of for C&C servers.
T1583.003
Purchase Infrastructure: Digital Personal Server
BladedFeline makes use of VPS companies to host C&C servers.
T1583
Purchase Infrastructure
BladedFeline makes use of IPs for community infrastructure, together with distributing malware and C&C servers.
T1586.002
Compromise Accounts: Electronic mail Accounts
BladedFeline makes use of compromised electronic mail accounts as C&C servers.
Preliminary Entry
T1190
Exploit Public-Going through Utility
BladedFeline in all probability exploits weak public-facing purposes for preliminary entry.
Execution
T1059.003
Command and Scripting Interpreter: Home windows Command Shell
BladedFeline makes use of the Home windows Command Shell to execute instructions on compromised endpoints.
T1059.007
Command and Scripting Interpreter: JavaScript
BladedFeline makes use of JavaScript webshells to execute instructions on compromised endpoints.
T1059.001
Command and Scripting Interpreter: PowerShell
BladedFeline makes use of PowerShell to execute instructions on compromised endpoints.
T1059.006
Command and Scripting Interpreter: Python
BladedFeline makes use of Python as a dropper for deploying backdoors to compromised endpoints.
T1559
Inter-Course of Communication
BladedFeline makes use of IPC as a method of native code execution in its malicious IIS module.
T1569.002
System Companies: Service Execution
BladedFeline makes use of Home windows companies for malware execution with Whisper and PrimeCache.
Persistence
T1547.001
Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder
The Whisper backdoor creates a LNK file within the startup folder for persistence.
T1546
Occasion Triggered Execution
PrimeCache is loaded by an IIS Employee Course of (w3wp.exe) when the IIS server receives an inbound HTTP request.
Protection Evasion
T1078
Legitimate Accounts
BladedFeline makes use of legit accounts to exfiltrate information and bypass defenses, and as C&C servers.
T1140
Deobfuscate/Decode Information or Data
The Whisper backdoor makes use of base64 encoding to obfuscate information.
T1070.004
Indicator Elimination: File Deletion
The Python dropper for Whisper deletes itself and different set up recordsdata after a profitable set up.
T1070.006
Indicator Elimination: Timestomp
BladedFeline routinely timestomps the compilation timestamps of malware that the group develops.
Credential Entry
T1003.001
OS Credential Dumping: LSASS Reminiscence
BladedFeline dumps LSASS from reminiscence to steal credentials.
Command and Management
T1573.001
Encrypted Channel: Symmetric Cryptography
The Whisper backdoor makes use of AES encryption to ship and obtain information between the malware and the C&C.
T1071.001
Utility Layer Protocol: Net Protocols
PrimeCache makes use of normal internet protocols for communication with the C&C server.
T1132.001
Information Encoding: Normal Encoding
PrimeCache makes use of normal encoding for communication with the C&C server.
T1573.002
Encrypted Channel: Uneven Cryptography
PrimeCache makes use of RSA and AES-CBC for C&C communication.
T1105
Ingress Device Switch
PrimeCache has the aptitude to obtain further recordsdata from the C&C server for native execution.
Exfiltration
T1048.001
Exfiltration Over Various Protocol: Exfiltration Over Symmetric Encrypted Non-C2 Protocol
The Whisper backdoor makes use of AES encryption and electronic mail inboxes to ship and obtain information between the malware and the C&C.
T1041
Exfiltration Over C2 Channel
PrimeCache exfiltrates information to a C&C server.