oski | b7bf04a5d5d14c38358fb28f8e2453bf45926684769ad6a79a4bf110d8587af5

General

Target

os.exe
Size

469KB
MD5

3e0559f907c481442d53ac625c3d98b0
SHA1

acad6550d0d9a43d791cd5aaf78237053ab2e9e2
SHA256

b7bf04a5d5d14c38358fb28f8e2453bf45926684769ad6a79a4bf110d8587af5
SHA512

1b05ea5c49483b68b420a0beb62039445288ac8325bb52b3ffa2a1de6a4241b261d2329db9d49df19fb909e042b199091c878c0b49a477cede7b4229ff548567

Score

10^/10

oski infostealer persistence spyware suricata

Malware Config

Extracted

Family

oski

C2

raslack.axwebsite.com

Signatures

Oski
Oski is an infostealer targeting browser data, crypto wallets.
infostealer oski
suricata: ET MALWARE Suspicious Zipped Filename in Outbound POST Request (Passwords.txt)
suricata: ET MALWARE Suspicious Zipped Filename in Outbound POST Request (Passwords.txt)
suricata
suricata: ET MALWARE Suspicious Zipped Filename in Outbound POST Request (Passwords.txt) M2
suricata: ET MALWARE Suspicious Zipped Filename in Outbound POST Request (Passwords.txt) M2
suricata
suricata: ET MALWARE Suspicious Zipped Filename in Outbound POST Request (passwords.txt) M2
suricata: ET MALWARE Suspicious Zipped Filename in Outbound POST Request (passwords.txt) M2
suricata
suricata: ET MALWARE Vidar/Arkei/Megumin/Oski Stealer Data Exfil
suricata: ET MALWARE Vidar/Arkei/Megumin/Oski Stealer Data Exfil
suricata
suricata: ET MALWARE Vidar/Arkei/Megumin/Oski Stealer HTTP POST Pattern
suricata: ET MALWARE Vidar/Arkei/Megumin/Oski Stealer HTTP POST Pattern
suricata
Downloads MZ/PE file
Loads dropped DLL 3 IoCs

Processes:

InstallUtil.exe

pid process

1984 InstallUtil.exe
1984 InstallUtil.exe
1984 InstallUtil.exe
Accesses cryptocurrency files/wallets, possible credential harvesting 2 TTPs
spyware

Data from Local System
T1005

Credentials in Files
T1081

pid	process
1984	InstallUtil.exe
1984	InstallUtil.exe
1984	InstallUtil.exe

Adds Run key to start application 2 TTPs 1 IoCs

persistence

Registry Run Keys / Startup Folder

T1060

Modify Registry

T1112

Processes:

os.exe

description	ioc	process
Set value (str)	\REGISTRY\USER\S-1-5-21-3440072777-2118400376-1759599358-1000\Software\Microsoft\Windows\CurrentVersion\Run\YESÇEXE = "\"C:\\Users\\Admin\\AppData\\Roaming\\YESÇEXE.exe\""	os.exe

Suspicious use of SetThreadContext 1 IoCs

Processes:

os.exe

description pid process target process

PID 588 set thread context of 1984 588 os.exe InstallUtil.exe
Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s). Likely ransomware behaviour.

System Information Discovery
T1082
Checks processor information in registry 2 TTPs 1 IoCs
Processor information is often read in order to detect sandboxing environments.

Query Registry
T1012

System Information Discovery
T1082

Processes:

InstallUtil.exe

description ioc process

Key value queried \REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0\ProcessorNameString InstallUtil.exe
Kills process with taskkill 1 IoCs
evasion

Processes:

taskkill.exe

pid process

964 taskkill.exe
Suspicious behavior: EnumeratesProcesses 2 IoCs

Processes:

powershell.exeos.exe

pid process

1560 powershell.exe
588 os.exe
Suspicious use of AdjustPrivilegeToken 3 IoCs

Processes:

powershell.exeos.exetaskkill.exe

description pid process

Token: SeDebugPrivilege 1560 powershell.exe
Token: SeDebugPrivilege 588 os.exe
Token: SeDebugPrivilege 964 taskkill.exe

description	pid	process	target process
PID 588 set thread context of 1984	588	os.exe	InstallUtil.exe

description	ioc	process
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0\ProcessorNameString	InstallUtil.exe

pid	process
964	taskkill.exe

pid	process
1560	powershell.exe
588	os.exe

description	pid	process
Token: SeDebugPrivilege	1560	powershell.exe
Token: SeDebugPrivilege	588	os.exe
Token: SeDebugPrivilege	964	taskkill.exe

Suspicious use of WriteProcessMemory 25 IoCs

Processes:

os.exeInstallUtil.execmd.exe

description	pid	process	target process
PID 588 wrote to memory of 1560	588	os.exe	powershell.exe
PID 588 wrote to memory of 1560	588	os.exe	powershell.exe
PID 588 wrote to memory of 1560	588	os.exe	powershell.exe
PID 588 wrote to memory of 1560	588	os.exe	powershell.exe
PID 588 wrote to memory of 1984	588	os.exe	InstallUtil.exe
PID 588 wrote to memory of 1984	588	os.exe	InstallUtil.exe
PID 588 wrote to memory of 1984	588	os.exe	InstallUtil.exe
PID 588 wrote to memory of 1984	588	os.exe	InstallUtil.exe
PID 588 wrote to memory of 1984	588	os.exe	InstallUtil.exe
PID 588 wrote to memory of 1984	588	os.exe	InstallUtil.exe
PID 588 wrote to memory of 1984	588	os.exe	InstallUtil.exe
PID 588 wrote to memory of 1984	588	os.exe	InstallUtil.exe
PID 588 wrote to memory of 1984	588	os.exe	InstallUtil.exe
PID 588 wrote to memory of 1984	588	os.exe	InstallUtil.exe
PID 588 wrote to memory of 1984	588	os.exe	InstallUtil.exe
PID 588 wrote to memory of 1984	588	os.exe	InstallUtil.exe
PID 588 wrote to memory of 1984	588	os.exe	InstallUtil.exe
PID 1984 wrote to memory of 784	1984	InstallUtil.exe	cmd.exe
PID 1984 wrote to memory of 784	1984	InstallUtil.exe	cmd.exe
PID 1984 wrote to memory of 784	1984	InstallUtil.exe	cmd.exe
PID 1984 wrote to memory of 784	1984	InstallUtil.exe	cmd.exe
PID 784 wrote to memory of 964	784	cmd.exe	taskkill.exe
PID 784 wrote to memory of 964	784	cmd.exe	taskkill.exe
PID 784 wrote to memory of 964	784	cmd.exe	taskkill.exe
PID 784 wrote to memory of 964	784	cmd.exe	taskkill.exe

C:\Users\Admin\AppData\Local\Temp\os.exe
"C:\Users\Admin\AppData\Local\Temp\os.exe"
1⤵
- Adds Run key to start application
- Suspicious use of SetThreadContext
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:588

C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
"C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -enc UwB0AGEAcgB0AC0AUwBsAGUAZQBwACAALQBTAGUAYwBvAG4AZABzACAAMgAwAA==
2⤵
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
PID:1560

C:\Windows\Microsoft.NET\Framework\v4.0.30319\InstallUtil.exe
C:\Windows\Microsoft.NET\Framework\v4.0.30319\InstallUtil.exe
2⤵
- Loads dropped DLL
- Checks processor information in registry
- Suspicious use of WriteProcessMemory
PID:1984

C:\Windows\SysWOW64\cmd.exe
"C:\Windows\System32\cmd.exe" /c taskkill /pid 1984 & erase C:\Windows\Microsoft.NET\Framework\v4.0.30319\InstallUtil.exe & RD /S /Q C:\\ProgramData\\236120598066915\\* & exit
3⤵
- Suspicious use of WriteProcessMemory
PID:784

C:\Windows\SysWOW64\taskkill.exe
taskkill /pid 1984
4⤵
- Kills process with taskkill
- Suspicious use of AdjustPrivilegeToken
PID:964

Network

MITRE ATT&CK Matrix ATT&CK v6

Initial Access

Execution

Persistence

Registry Run Keys / Startup Folder

1

T1060

Privilege Escalation

Defense Evasion

Modify Registry

1

T1112

Credential Access

Credentials in Files

1

T1081

Discovery

System Information Discovery

2

T1082

Query Registry

1

T1012

Lateral Movement

Collection

Data from Local System

1

T1005

Exfiltration

Command and Control

Impact

Replay Monitor

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Downloads

\ProgramData\mozglue.dll
Filesize
133KB

MD5
8f73c08a9660691143661bf7332c3c27

SHA1
37fa65dd737c50fda710fdbde89e51374d0c204a

SHA256
3fe6b1c54b8cf28f571e0c5d6636b4069a8ab00b4f11dd842cfec00691d0c9cd

SHA512
0042ecf9b3571bb5eba2de893e8b2371df18f7c5a589f52ee66e4bfbaa15a5b8b7cc6a155792aaa8988528c27196896d5e82e1751c998bacea0d92395f66ad89

Download Submit
\ProgramData\nss3.dll
Filesize
1.2MB

MD5
bfac4e3c5908856ba17d41edcd455a51

SHA1
8eec7e888767aa9e4cca8ff246eb2aacb9170428

SHA256
e2935b5b28550d47dc971f456d6961f20d1633b4892998750140e0eaa9ae9d78

SHA512
2565bab776c4d732ffb1f9b415992a4c65b81bcd644a9a1df1333a269e322925fc1df4f76913463296efd7c88ef194c3056de2f1ca1357d7b5fe5ff0da877a66

Download Submit
\ProgramData\sqlite3.dll
Filesize
630KB

MD5
e477a96c8f2b18d6b5c27bde49c990bf

SHA1
e980c9bf41330d1e5bd04556db4646a0210f7409

SHA256
16574f51785b0e2fc29c2c61477eb47bb39f714829999511dc8952b43ab17660

SHA512
335a86268e7c0e568b1c30981ec644e6cd332e66f96d2551b58a82515316693c1859d87b4f4b7310cf1ac386cee671580fdd999c3bcb23acf2c2282c01c8798c

Download Submit
memory/588-55-0x0000000000270000-0x00000000002DE000-memory.dmp

Filesize
440KB

Download
memory/588-56-0x0000000004850000-0x00000000048E2000-memory.dmp

Filesize
584KB

Download
memory/588-57-0x0000000076231000-0x0000000076233000-memory.dmp

Filesize
8KB

Download
memory/588-54-0x00000000001F0000-0x0000000000268000-memory.dmp

Filesize
480KB

Download
memory/784-81-0x0000000000000000-mapping.dmp

Download
memory/964-83-0x0000000000000000-mapping.dmp

Download
memory/1560-62-0x000000006FAA0000-0x000000007004B000-memory.dmp

Filesize
5.7MB

Download
memory/1560-61-0x000000006FAA0000-0x000000007004B000-memory.dmp

Filesize
5.7MB

Download
memory/1560-60-0x000000006FAA0000-0x000000007004B000-memory.dmp

Filesize
5.7MB

Download
memory/1560-58-0x0000000000000000-mapping.dmp

Download
memory/1984-66-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/1984-73-0x000000000040717B-mapping.dmp

Download
memory/1984-75-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/1984-77-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/1984-72-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/1984-70-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/1984-68-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/1984-64-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/1984-82-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/1984-63-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

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Analysis

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