ESET researchers have analyzed two campaigns by the OilRig APT group: Outer Area (2021), and Juicy Combine (2022). Each of those cyberespionage campaigns focused Israeli organizations solely, which is consistent with the group’s deal with the Center East, and used the identical playbook: OilRig first compromised a reliable web site to make use of as a C&C server after which used VBS droppers to ship a C#/.NET backdoor to its victims, whereas additionally deploying quite a lot of post-compromise instruments largely used for knowledge exfiltration on the goal techniques.
Of their Outer Area marketing campaign, OilRig used a easy, beforehand undocumented C#/.NET backdoor we named Photo voltaic, together with a brand new downloader, SampleCheck5000 (or SC5k), that makes use of the Microsoft Workplace Trade Internet Companies API for C&C communication. For the Juicy Combine marketing campaign, the risk actors improved on Photo voltaic to create the Mango backdoor, which possesses further capabilities and obfuscation strategies. Along with detecting the malicious toolset, we additionally notified the Israeli CERT in regards to the compromised web sites.
Key factors of this blogpost:
ESET noticed two OilRig campaigns which occurred all through 2021 (Outer Area) and 2022 (Juicy Combine).
The operators solely focused Israeli organizations and compromised reliable Israeli web sites to be used of their C&C communications.
They used a brand new, beforehand undocumented C#/.NET first-stage backdoor in every marketing campaign: Photo voltaic in Outer Area, then its successor Mango in Juicy Combine.
Each backdoors had been deployed by VBS droppers, presumably unfold by way of spearphishing emails.
Quite a lot of post-compromise instruments had been deployed in each campaigns, notably the SC5k downloader that makes use of Microsoft Workplace Trade Internet Companies API for C&C communication, and a number of other instruments to steal browser knowledge and credentials from Home windows Credential Supervisor.
OilRig, often known as APT34, Lyceum, or Siamesekitten, is a cyberespionage group that has been lively since not less than 2014 and is often believed to be based mostly in Iran. The group targets Center Japanese governments and quite a lot of enterprise verticals, together with chemical, vitality, monetary, and telecommunications. OilRig carried out the DNSpionage marketing campaign in 2018 and 2019, which focused victims in Lebanon and the United Arab Emirates. In 2019 and 2020, OilRig continued assaults with the HardPass marketing campaign, which used LinkedIn to focus on Center Japanese victims within the vitality and authorities sectors. In 2021, OilRig up to date its DanBot backdoor and started deploying the Shark, Milan, and Marlin backdoors, talked about within the T3 2021 challenge of the ESET Menace Report.
On this blogpost, we offer technical evaluation of the Photo voltaic and Mango backdoors, of the VBS dropper used to ship Mango, and of the post-compromise instruments deployed in every marketing campaign.
Attribution
The preliminary hyperlink that allowed us to attach the Outer Area marketing campaign to OilRig is the usage of the identical customized Chrome knowledge dumper (tracked by ESET researchers below the title MKG) as within the Out to Sea marketing campaign. We noticed the Photo voltaic backdoor deploy the exact same pattern of MKG as in Out to Sea on the goal’s system, together with two different variants.
Moreover the overlap in instruments and focusing on, we additionally noticed a number of similarities between the Photo voltaic backdoor and the backdoors utilized in Out to Sea, largely associated to add and obtain: each Photo voltaic and Shark, one other OilRig backdoor, use URIs with easy add and obtain schemes to speak with the C&C server, with a “d” for obtain and a “u” for add; moreover, the downloader SC5k makes use of uploads and downloads subdirectories identical to different OilRig backdoors, particularly ALMA, Shark, DanBot, and Milan. These findings function an additional affirmation that the offender behind Outer Area is certainly OilRig.
As for the Juicy Combine marketing campaign’s ties to OilRig, apart from focusing on Israeli organizations – which is typical for this espionage group – there are code similarities between Mango, the backdoor used on this marketing campaign, and Photo voltaic. Furthermore, each backdoors had been deployed by VBS droppers with the identical string obfuscation method. The selection of post-compromise instruments employed in Juicy Combine additionally mirrors earlier OilRig campaigns.
Outer Area marketing campaign overview
Named for the usage of an astronomy-based naming scheme in its operate names and duties, Outer Area is an OilRig marketing campaign from 2021. On this marketing campaign, the group compromised an Israeli human sources website and subsequently used it as a C&C server for its beforehand undocumented C#/.NET backdoor, Photo voltaic. Photo voltaic is an easy backdoor with primary performance comparable to studying and writing from disk, and gathering data.
By way of Photo voltaic, the group then deployed a brand new downloader SC5k, which makes use of the Workplace Trade Internet Companies API to obtain further instruments for execution, as proven in Determine 1. With a view to exfiltrate browser knowledge from the sufferer’s system, OilRig used a Chrome-data dumper known as MKG.
Juicy Combine marketing campaign overview
In 2022 OilRig launched one other marketing campaign focusing on Israeli organizations, this time with an up to date toolset. We named the marketing campaign Juicy Combine for the usage of a brand new OilRig backdoor, Mango (based mostly on its inside meeting title, and its filename, Mango.exe). On this marketing campaign, the risk actors compromised a reliable Israeli job portal web site to be used in C&C communications. The group’s malicious instruments had been then deployed towards a healthcare group, additionally based mostly in Israel.
The Mango first-stage backdoor is a successor to Photo voltaic, additionally written in C#/.NET, with notable modifications that embrace exfiltration capabilities, use of native APIs, and added detection evasion code.
Together with Mango, we additionally detected two beforehand undocumented browser-data dumpers used to steal cookies, shopping historical past, and credentials from the Chrome and Edge browsers, and a Home windows Credential Supervisor stealer, all of which we attribute to OilRig. These instruments had been all used towards the identical goal as Mango, in addition to at different compromised Israeli organizations all through 2021 and 2022. Determine 2 reveals an summary of how the varied parts had been used within the Juicy Combine marketing campaign.
Technical evaluation
On this part, we offer a technical evaluation of the Photo voltaic and Mango backdoors and the SC5k downloader, in addition to different instruments that had been deployed to the focused techniques in these campaigns.
VBS droppers
To ascertain a foothold on the goal’s system, Visible Fundamental Script (VBS) droppers had been utilized in each campaigns, which had been very seemingly unfold by spearphishing emails. Our evaluation under focuses on the VBS script used to drop Mango (SHA-1: 3699B67BF4E381847BF98528F8CE2B966231F01A); notice that Photo voltaic’s dropper could be very comparable.
The dropper’s objective is to ship the embedded Mango backdoor, schedule a activity for persistence, and register the compromise with the C&C server. The embedded backdoor is saved as a collection of base64 substrings, that are concatenated and base64 decoded. As proven in Determine 3, the script additionally makes use of a easy string deobfuscation method, the place strings are assembled utilizing arithmetic operations and the Chr operate.
On high of that, Mango’s VBS dropper provides one other sort of string obfuscation and code to arrange persistence and register with the C&C server. As proven in Determine 4, to deobfuscate some strings, the script replaces any characters within the set #*+-_)(}{@$%^& with 0, then divides the string into three-digit numbers which can be then transformed into ASCII characters utilizing the Chr operate. For instance, the string 116110101109117+99111$68+77{79$68}46-50108109120115}77 interprets to Msxml2.DOMDocument.
As soon as the backdoor is embedded on the system, the dropper strikes on to create a scheduled activity that executes Mango (or Photo voltaic, within the different model) each 14 minutes. Lastly, the script sends a base64-encoded title of the compromised pc by way of a POST request to register the backdoor with its C&C server.
Photo voltaic backdoor
Photo voltaic is the backdoor utilized in OilRig’s Outer Area marketing campaign. Possessing primary functionalities, this backdoor can be utilized to, amongst different issues, obtain and execute information, and routinely exfiltrate staged information.
We selected the title Photo voltaic based mostly on the filename utilized by OilRig, Photo voltaic.exe. It’s a becoming title because the backdoor makes use of an astronomy naming scheme for its operate names and duties used all through the binary (Mercury, Venus, Mars, Earth, and Jupiter).
Photo voltaic begins execution by performing the steps proven in Determine 5.
The backdoor creates two duties, Earth and Venus, that run in reminiscence. There isn’t any cease operate for both of the 2 duties, so they’ll run indefinitely. Earth is scheduled to run each 30 seconds and Venus is ready to run each 40 seconds.
Earth is the first activity, answerable for the majority of Photo voltaic’s capabilities. It communicates with the C&C server utilizing the operate MercuryToSun, which sends primary system and malware model data to the C&C server after which handles the server’s response. Earth sends the next data to the C&C server:
The string (@) <system hostname>; the entire string is encrypted.
The string 1.0.0.0, encrypted (presumably a model quantity).
The string 30000, encrypted (presumably the scheduled runtime of Earth in milliseconds).
Encryption and decryption are applied in capabilities named JupiterE and JupiterD, respectively. Each of them name a operate named JupiterX, which implements an XOR loop as proven in Determine 6.
The secret is derived from a hardcoded international string variable, 6sEj7*0B7#7, and a nonce: on this case, a random hex string from 2–24 characters lengthy. Following the XOR encryption, customary base64 encoding is utilized.
An Israeli human sources firm’s internet server, which OilRig compromised sooner or later earlier than deploying Photo voltaic, was used because the C&C server:
http://group.co[.]il/venture/templates/workplace/template.aspx?rt=d&solar=<encrypted_MachineGuid>&rn=<encryption_nonce>
Previous to being appended to the URI, the encryption nonce is encrypted, and the worth of the preliminary question string, rt, is ready to d right here, seemingly for “obtain”.
The final step of the MercuryToSun operate is to course of a response from the C&C server. It does so by retrieving a substring of the response, which is discovered between the characters QQ@ and @kk. This response is a string of directions separated by asterisks (*) that’s processed into an array. Earth then carries out the backdoor instructions, which embrace downloading further payloads from the server, itemizing information on the sufferer’s system, and operating particular executables.
Command output is then gzip compressed utilizing the operate Neptune and encrypted with the identical encryption key and a brand new nonce. Then the outcomes are uploaded to the C&C server, thus:
http://<redacted>.co[.]il/venture/templates/workplace/template.aspx?rt=u&solar=<MachineGuid>&rn=<new_nonce>
MachineGuid and the brand new nonce are encrypted with the JupiterE operate, and right here the worth of rt is ready to u, seemingly for “add”.
Venus, the opposite scheduled activity, is used for automated knowledge exfiltration. This small activity copies the content material of information from a listing (additionally named Venus) to the C&C server. These information are seemingly dropped right here by another, as but unidentified, OilRig device. After importing a file, the duty deletes it from disk.
Mango backdoor
For its Juicy Combine marketing campaign, OilRig switched from the Photo voltaic backdoor to Mango. It has the same workflow to Photo voltaic and overlapping capabilities, however there are however a number of notable modifications:
Use of TLS for C&C communications.
Use of native APIs, quite than .NET APIs, to execute information and shell instructions.
Though not actively used, detection evasion code was launched.
Assist for automated exfiltration (Venus in Photo voltaic) has been eliminated; as an alternative, Mango helps a further backdoor command for exfiltrating chosen information.
Assist for log mode has been eliminated, and image names have been obfuscated.
Opposite to Photo voltaic’s astronomy-themed naming scheme, Mango obfuscates its image names, as could be seen in Determine 7.
Moreover the image title obfuscation, Mango additionally makes use of the string stacking methodology (as proven in Determine 8) to obfuscate strings, which complicates the usage of easy detection strategies.
Much like Photo voltaic, the Mango backdoor begins by creating an in-memory activity, scheduled to run indefinitely each 32 seconds. This activity communicates with the C&C server and executes backdoor instructions, just like Photo voltaic’s Earth activity. Whereas Photo voltaic additionally creates Venus, a activity for automated exfiltration, this performance has been changed in Mango by a brand new backdoor command.
In the principle activity, Mango first generates a sufferer identifier, <victimID>, for use in C&C communications. The ID is computed as an MD5 hash of <machine title><username>, formatted as a hexadecimal string.
To request a backdoor command, Mango then sends the string d@<victimID>@<machine title>|<username> to the C&C server http://www.darush.co[.]il/advertisements.asp – a reliable Israeli job portal, seemingly compromised by OilRig earlier than this marketing campaign. We notified the Israeli nationwide CERT group in regards to the compromise.
The request physique is constructed as follows:
The information to be transmitted is XOR encrypted utilizing the encryption key Q&4g, then base64 encoded.
A pseudorandom string of three–14 characters is generated from this alphabet (because it seems within the code): i8p3aEeKQbN4klFMHmcC2dU9f6gORGIhDBLS0jP5Tn7o1AVJ.
The encrypted knowledge is inserted in a pseudorandom place inside the generated string, enclosed between [@ and @] delimiters.
To speak with its C&C server, Mango makes use of the TLS (Transport Layer Safety) protocol, which is used to supply a further layer of encryption.
Equally, the backdoor command obtained from the C&C server is XOR encrypted, base64 encoded, after which enclosed between [@ and @] inside the HTTP response physique. The command itself is both NCNT (wherein case no motion is taken), or a string of a number of parameters delimited by @, as detailed in Desk 1, which lists Mango’s backdoor instructions. Be aware that <Arg0> isn’t listed within the desk, however is used within the response to the C&C server.
Desk 1. Checklist of Mango’s backdoor instructions
Arg1
Arg2
Arg3
Motion taken
Return worth
1 or empty string
+sp <elective arguments>
N/A
Executes the desired file/shell command (with the elective arguments), utilizing the native CreateProcess API imported by way of DllImport. If the arguments comprise [s], it’s changed by C:WindowsSystem32.
Command output.
+nu
N/A
Returns the malware model string and C&C URL.
<versionString>|<c2URL>; on this case:
1.0.0|http://www.darush.co[.]il/advertisements.asp
+fl <elective listing title>
N/A
Enumerates the content material of the desired listing (or present working listing).
Listing of <listing path>
For every subdirectory:
<last_write_time> <DIR> <subdirectory title>
For every file:
<last_write_time> FILE <file dimension> <filename>
<variety of subdirectories> Dir(s)
<variety of information> File(s)
+dn <file title>
N/A
Uploads the file content material to the C&C server by way of a brand new HTTP POST request formatted: u@<victimID>@<machine title>|<username>@<file path>@2@<base64encodedFileContent>.
Considered one of:
· file[<filename>] is uploaded to server.
· file not discovered!
· file path empty!
2
Base64-encoded knowledge
Filename
Dumps the desired knowledge right into a file within the working listing.
file downloaded to path[<fullFilePath>]
Every backdoor command is dealt with in a brand new thread, and their return values are then base64 encoded and mixed with different metadata. Lastly, that string is shipped to the C&C server utilizing the identical protocol and encryption methodology as described above.
Unused detection evasion method
Apparently, we discovered an unused detection evasion method inside Mango. The operate answerable for executing information and instructions downloaded from the C&C server takes an elective second parameter – a course of ID. If set, Mango then makes use of the UpdateProcThreadAttribute API to set the PROC_THREAD_ATTRIBUTE_MITIGATION_POLICY (0x20007) attribute for the desired course of to worth: PROCESS_CREATION_MITIGATION_POLICY_BLOCK_NON_MICROSOFT_BINARIES_ALWAYS_ON (0x100000000000), as proven in Determine 9.
This system’s purpose is to dam endpoint safety options from loading their user-mode code hooks by way of a DLL on this course of. Whereas the parameter was not used within the pattern we analyzed, it may very well be activated in future variations.
Model 1.1.1
Unrelated to the Juicy Combine marketing campaign, in July 2023 we discovered a brand new model of the Mango backdoor (SHA-1: C9D18D01E1EC96BE952A9D7BD78F6BBB4DD2AA2A), uploaded to VirusTotal by a number of customers below the title Menorah.exe. The inner model on this pattern was modified from 1.0.0 to 1.1.1, however the one notable change is the usage of a special C&C server, http://tecforsc-001-site1.gtempurl[.]com/advertisements.asp.
Together with this model, we additionally found a Microsoft Phrase doc (SHA-1: 3D71D782B95F13EE69E96BCF73EE279A00EAE5DB) with a malicious macro that drops the backdoor. Determine 10 reveals the faux warning message, engaging the person to allow macros for the doc, and the decoy content material that’s displayed afterwards, whereas the malicious code is operating within the background.
Determine 10. Microsoft Phrase doc with a malicious macro that drops Mango v1.1.1
Publish-compromise instruments
On this part, we overview a choice of post-compromise instruments utilized in OilRig’s Outer Area and Juicy Combine campaigns, aimed toward downloading and executing further payloads, and stealing knowledge from the compromised techniques.
SampleCheck5000 (SC5k) downloader
SampleCheck5000 (or SC5k) is a downloader used to obtain and execute further OilRig instruments, notable for utilizing the Microsoft Workplace Trade Internet Companies API for C&C communication: the attackers create draft messages on this electronic mail account and conceal the backdoor instructions in there. Subsequently, the downloader logs into the identical account, and parses the drafts to retrieve instructions and payloads to execute.
SC5k makes use of predefined values – Microsoft Trade URL, electronic mail deal with, and password – to log into the distant Trade server, nevertheless it additionally helps the choice to override these values utilizing a configuration file within the present working listing named setting.key. We selected the title SampleCheck5000 based mostly on one of many electronic mail addresses that the device used within the Outer Area marketing campaign.
As soon as SC5k logs into the distant Trade server, it retrieves all of the emails within the Drafts listing, kinds them by most up-to-date, conserving solely the drafts which have attachments. It then iterates over each draft message with an attachment, on the lookout for JSON attachments that comprise “knowledge” within the physique. It extracts the worth from the important thing knowledge within the JSON file, base64 decodes and decrypts the worth, and calls cmd.exe to execute the ensuing command line string. SC5k then saves the output of the cmd.exe execution to a neighborhood variable.
As the subsequent step within the loop, the downloader studies the outcomes to the OilRig operators by creating a brand new electronic mail message on the Trade server and saving it as a draft (not sending), as proven in Determine 11. An identical method is used to exfiltrate information from a neighborhood staging folder. Because the final step within the loop, SC5k additionally logs the command output in an encrypted and compressed format on disk.
Browser-data dumpers
It’s attribute of OilRig operators to make use of browser-data dumpers of their post-compromise actions. We found two new browser-data stealers among the many post-compromise instruments deployed within the Juicy Combine marketing campaign alongside the Mango backdoor. They dump the stolen browser knowledge within the %TEMP% listing into information named Cupdate and Eupdate (therefore our names for them: CDumper and EDumper).
Each instruments are C#/.NET browser-data stealers, gathering cookies, shopping historical past, and credentials from the Chrome (CDumper) and Edge (EDumper) browsers. We focus our evaluation on CDumper, since each stealers are virtually equivalent, save for some constants.
When executed, CDumper creates an inventory of customers with Google Chrome put in. On execution, the stealer connects to the Chrome SQLite Cookies, Historical past and Login Knowledge databases below %APPDATApercentLocalGoogleChromeUser Knowledge, and collects browser knowledge together with visited URLs and saved logins, utilizing SQL queries.
The cookie values are then decrypted, and all collected data is added to a log file named C:Customers<person>AppDataLocalTempCupdate, in cleartext. This performance is applied in CDumper capabilities named CookieGrab (see Determine 12), HistoryGrab, and PasswordGrab. Be aware that there isn’t a exfiltration mechanism applied in CDumper, however Mango can exfiltrate chosen information by way of a backdoor command.
In each Outer Area and the sooner Out to Sea marketing campaign, OilRig used a C/C++ Chrome knowledge dumper known as MKG. Like CDumper and EDumper, MKG was additionally in a position to steal usernames and passwords, shopping historical past, and cookies from the browser. This Chrome knowledge dumper is usually deployed within the following file areas (with the primary location being the most typical):
%USERSpercentpublicprogramsvmwaredir<random_14_character_string>mkc.exe
%USERSpercentPublicM64.exe
Home windows Credential Supervisor stealer
Moreover browser-data dumping instruments, OilRig additionally used a Home windows Credential Supervisor stealer within the Juicy Combine marketing campaign. This device steals credentials from Home windows Credential Supervisor, and just like CDumper and EDumper, shops them within the %TEMP% listing – this time right into a file named IUpdate (therefore the title IDumper). Not like CDumper and EDumper, IDumper is applied as a PowerShell script.
As with the browser dumper instruments, it’s not unusual for OilRig to gather credentials from the Home windows Credential Supervisor. Beforehand, OilRig’s operators had been noticed utilizing VALUEVAULT, a publicly accessible, Go-compiled credential-theft device (see the 2019 HardPass marketing campaign and a 2020 marketing campaign), for a similar objective.
Conclusion
OilRig continues to innovate and create new implants with backdoor-like capabilities whereas discovering new methods to execute instructions on distant techniques. The group improved upon its C#/.NET Photo voltaic backdoor from the Outer Area marketing campaign to create a brand new backdoor named Mango for the Juicy Combine marketing campaign. The group deploys a set of customized post-compromise instruments which can be used to gather credentials, cookies, and shopping historical past from main browsers and from the Home windows Credential Supervisor. Regardless of these improvements, OilRig additionally continues to depend on established methods to acquire person knowledge.
For any inquiries about our analysis printed on WeLiveSecurity, please contact us at threatintel@eset.com.ESET Analysis presents personal APT intelligence studies and knowledge feeds. For any inquiries about this service, go to the ESET Menace Intelligence web page.
IoCs
Recordsdata
SHA-1
Filename
ESET detection title
Description
3D71D782B95F13EE69E96BCF73EE279A00EAE5DB
MyCV.doc
VBA/OilRig.C
Doc with malicious macro dropping Mango.
3699B67BF4E381847BF98528F8CE2B966231F01A
chrome_log.vbs
VBS/TrojanDropper.Agent.PCC
VBS dropper.
1DE4810A10FA2D73CC589CA403A4390B02C6DA5E
Photo voltaic.exe
MSIL/OilRig.E
Photo voltaic backdoor.
CB26EBDE498ECD2D7CBF1BC498E1BCBB2619A96C
Mango.exe
MSIL/OilRig.E
Mango backdoor (v1.0.0).
C9D18D01E1EC96BE952A9D7BD78F6BBB4DD2AA2A
Menorah.exe
MSIL/OilRig.E
Mango backdoor (v1.1.1).
83419CBA55C898FDBE19DFAFB5B1B207CC443190
EdgeUpdater.exe
MSIL/PSW.Agent.SXJ
Edge knowledge dumper.
DB01095AFEF88138C9ED3847B5D8AF954ED7BBBC
Gr.exe
MSIL/PSW.Agent.SXJ
Chrome knowledge dumper.
BE01C95C2B5717F39B550EA20F280D69C0C05894
ieupdater.exe
PowerShell/PSW.Agent.AH
Home windows Credential Supervisor dumper.
6A1BA65C9FD8CC9DCB0657977DB2B03DACDD8A2A
mkc.exe
Win64/PSW.Agent.AW
MKG – Chrome knowledge dumper.
94C08A619AF2B08FEF08B131A7A59D115C8C2F7B
mkkc.exe
Win64/PSW.Agent.AW
MKG – Chrome knowledge dumper.
CA53B8EB76811C1940D814AAA8FE875003805F51
cmk.exe
Win64/PSW.Agent.AW
MKG – Chrome knowledge dumper.
BE9B6ACA8A175DF61F2C75932E029F19789FD7E3
CCXProcess.exe
MSIL/OilRig.A
SC5k downloader (32-bit model).
2236D4DCF68C65A822FF0A2AD48D4DF99761AD07
acrotray.exe
MSIL/OilRig.D
SC5k downloader (64-bit model).
EA8C3E9F418DCF92412EB01FCDCDC81FDD591BF1
node.exe
MSIL/OilRig.D
SC5k downloader (64-bit model).
Community
IP
Area
Internet hosting supplier
First seen
Particulars
199.102.48[.]42
tecforsc-001-site1.gtempurl[.]com
MarquisNet
2022-07-29
N/A
MITRE ATT&CK strategies
This desk was constructed utilizing model 13 of the MITRE ATT&CK framework.
Tactic
ID
Title
Description
Useful resource Improvement
T1584.004
Compromise Infrastructure: Server
In each Outer Area and Juicy Combine campaigns, OilRig has compromised reliable web sites to stage malicious instruments and for C&C communications.
T1587.001
Develop Capabilities: Malware
OilRig has developed customized backdoors (Photo voltaic and Mango), a downloader (SC5k), and a set of credential-theft instruments to be used in its operations.
T1608.001
Stage Capabilities: Add Malware
OilRig has uploaded malicious parts to its C&C servers, and saved prestaged information and instructions within the Drafts electronic mail listing of an Workplace 365 account for SC5k to obtain and execute.
T1608.002
Stage Capabilities: Add Device
OilRig has uploaded malicious instruments to its C&C servers, and saved prestaged information within the Drafts electronic mail listing of an Workplace 365 account for SC5k to obtain and execute.
Preliminary Entry
T1566.001
Phishing: Spearphishing Attachment
OilRig in all probability distributed its Outer Area and Juicy Combine campaigns by way of phishing emails with their VBS droppers hooked up.
Execution
T1053.005
Scheduled Activity/Job: Scheduled Activity
OilRig’s IDumper, EDumper, and CDumper instruments use scheduled duties named ie<person>, ed<person>, and cu<person> to execute themselves below the context of different customers.
Photo voltaic and Mango use a C#/.NET activity on a timer to iteratively execute their principal capabilities.
T1059.001
Command and Scripting Interpreter: PowerShell
OilRig’s IDumper device makes use of PowerShell for execution.
T1059.003
Command and Scripting Interpreter: Home windows Command Shell
OilRig’s Photo voltaic, SC5k, IDumper, EDumper, and CDumper use cmd.exe to execute duties on the system.
T1059.005
Command and Scripting Interpreter: Visible Fundamental
OilRig makes use of a malicious VBScript to ship and persist its Photo voltaic and Mango backdoors.
T1106
Native API
OilRig’s Mango backdoor makes use of the CreateProcess Home windows API for execution.
Persistence
T1053.005
Scheduled Activity/Job: Scheduled Activity
OilRig’s VBS dropper schedules a activity named ReminderTask to ascertain persistence for the Mango backdoor.
Protection Evasion
T1036.005
Masquerading: Match Legit Title or Location
OilRig makes use of reliable or innocuous filenames for its malware to disguise itself from defenders and safety software program.
T1027.002
Obfuscated Recordsdata or Info: Software program Packing
OilRig has used SAPIEN Script Packager and SmartAssembly obfuscator to obfuscate its IDumper device.
T1027.009
Obfuscated Recordsdata or Info: Embedded Payloads
OilRig’s VBS droppers have malicious payloads embedded inside them as a collection of base64 substrings.
T1036.004
Masquerading: Masquerade Activity or Service
With a view to seem reliable, Mango’s VBS dropper schedules a activity with the outline Begin notepad at a sure time.
T1070.009
Indicator Elimination: Clear Persistence
OilRig’s post-compromise instruments delete their scheduled duties after a sure time interval.
T1140
Deobfuscate/Decode Recordsdata or Info
OilRig makes use of a number of obfuscation strategies to guard its strings and embedded payloads.
T1553
Subvert Belief Controls
SC5k makes use of Workplace 365, usually a trusted third celebration and sometimes missed by defenders, as a obtain website.
T1562
Impair Defenses
OilRig’s Mango backdoor has an (as but) unused functionality to dam endpoint safety options from loading their user-mode code in particular processes.
Credential Entry
T1555.003
Credentials from Password Shops: Credentials from Internet Browsers
OilRig’s customized instruments MKG, CDumper, and EDumper can acquire credentials, cookies, and shopping historical past from Chrome and Edge browsers.
T1555.004
Credentials from Password Shops: Home windows Credential Supervisor
OilRig’s customized credential dumping device IDumper can steal credentials from the Home windows Credential Supervisor.
Discovery
T1082
System Info Discovery
Mango obtains the compromised pc title.
T1083
File and Listing Discovery
Mango has a command to enumerate the content material of a specified listing.
T1033
System Proprietor/Consumer Discovery
Mango obtains the sufferer’s username.
T1087.001
Account Discovery: Native Account
OilRig’s EDumper, CDumper, and IDumper instruments can enumerate all person accounts on the compromised host.
T1217
Browser Info Discovery
MKG dumps Chrome historical past and bookmarks.
Command and Management
T1071.001
Software Layer Protocol: Internet Protocols
Mango makes use of HTTP in C&C communications.
T1105
Ingress Device Switch
Mango has the potential to obtain further information from the C&C server for subsequent execution.
T1001
Knowledge Obfuscation
Photo voltaic and SC5k use a easy XOR-encryption methodology together with gzip compression to obfuscate knowledge at relaxation and in transit.
T1102.002
Internet Service: Bidirectional Communication
SC5k makes use of Workplace 365 for downloading information from and importing information to the Drafts listing in a reliable electronic mail account.
T1132.001
Knowledge Encoding: Customary Encoding
Photo voltaic, Mango, and MKG base64 decodes knowledge earlier than sending it to the C&C server.
T1573.001
Encrypted Channel: Symmetric Cryptography
Mango makes use of an XOR cipher with the important thing Q&4g to encrypt knowledge in C&C communication.
T1573.002
Encrypted Channel: Uneven Cryptography
Mango makes use of TLS for C&C communication.
Exfiltration
T1041
Exfiltration Over C2 Channel
Mango, Photo voltaic, and SC5k use their C&C channels for exfiltration.
