oski | 614ea8187654128fc27a51455ab3c8fdbb6d398382cd4d825cf795dbbf5d7966

General

Target
542f3ea693d61187bd10db0376a6b3e7.exe
Size 256KB
Sample210420-4mpgp71lfs
SHA256 614ea8187654128fc27a51455ab3c8fdbb6d398382cd4d825cf795dbbf5d7966
MD5 542f3ea693d61187bd10db0376a6b3e7
SHA1 92409ffc8c6ea0ae55a76b6b15616f75174dba97
SHA512 cb383f540285ceb9232a4cc807b5287c4145f6c62fbf961385ef97a68034cc07c37337a595c403dbfe073ad0eac39ce765d58914856051a4c413d6ee5dbc4fb1
MD5 SHA1 SHA512

Score

10^/10

Family

C2

Oski
Oski is an infostealer targeting browser data, crypto wallets.
infostealer oski
Downloads MZ/PE file

Loads dropped DLL 3 IoCs

Reads user/profile data of web browsers 2 TTPs
Infostealers often target stored browser data, which can include saved credentials etc.
spyware stealer

Data from Local System
T1005

Credentials in Files
T1081
Accesses cryptocurrency files/wallets, possible credential harvesting 2 TTPs
spyware

Data from Local System
T1005

Credentials in Files
T1081

Adds Run key to start application 2 TTPs 1 IoCs

Registry Run Keys / Startup Folder

Modify Registry

description	ioc	Process
Set value (str)	\REGISTRY\USER\S-1-5-21-3686645723-710336880-414668232-1000\Software\Microsoft\Windows\CurrentVersion\Run\note = "\"C:\\Users\\Admin\\AppData\\Local\\note.exe\""	542f3ea693d61187bd10db0376a6b3e7.exe

Checks installed software on the system 1 TTPs
Looks up Uninstall key entries in the registry to enumerate software on the system.
discovery

Query Registry
T1012

Suspicious use of SetThreadContext 1 IoCs

description	pid	Process	procid_target
PID 2008 set thread context of 4000	2008	542f3ea693d61187bd10db0376a6b3e7.exe	80

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

System Information Discovery

description	ioc	Process
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0\ProcessorNameString	542f3ea693d61187bd10db0376a6b3e7.exe

Kills process with taskkill 1 IoCs

evasion

pid	Process
3076	taskkill.exe

Suspicious behavior: EnumeratesProcesses 6 IoCs

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	2008	542f3ea693d61187bd10db0376a6b3e7.exe
Token: SeDebugPrivilege	3076	taskkill.exe

Suspicious use of WriteProcessMemory 18 IoCs

description	pid	Process	procid_target
PID 2008 wrote to memory of 2596	2008	542f3ea693d61187bd10db0376a6b3e7.exe	79
PID 2008 wrote to memory of 2596	2008	542f3ea693d61187bd10db0376a6b3e7.exe	79
PID 2008 wrote to memory of 2596	2008	542f3ea693d61187bd10db0376a6b3e7.exe	79
PID 2008 wrote to memory of 4000	2008	542f3ea693d61187bd10db0376a6b3e7.exe	80
PID 2008 wrote to memory of 4000	2008	542f3ea693d61187bd10db0376a6b3e7.exe	80
PID 2008 wrote to memory of 4000	2008	542f3ea693d61187bd10db0376a6b3e7.exe	80
PID 2008 wrote to memory of 4000	2008	542f3ea693d61187bd10db0376a6b3e7.exe	80
PID 2008 wrote to memory of 4000	2008	542f3ea693d61187bd10db0376a6b3e7.exe	80
PID 2008 wrote to memory of 4000	2008	542f3ea693d61187bd10db0376a6b3e7.exe	80
PID 2008 wrote to memory of 4000	2008	542f3ea693d61187bd10db0376a6b3e7.exe	80
PID 2008 wrote to memory of 4000	2008	542f3ea693d61187bd10db0376a6b3e7.exe	80
PID 2008 wrote to memory of 4000	2008	542f3ea693d61187bd10db0376a6b3e7.exe	80
PID 4000 wrote to memory of 4008	4000	542f3ea693d61187bd10db0376a6b3e7.exe	81
PID 4000 wrote to memory of 4008	4000	542f3ea693d61187bd10db0376a6b3e7.exe	81
PID 4000 wrote to memory of 4008	4000	542f3ea693d61187bd10db0376a6b3e7.exe	81
PID 4008 wrote to memory of 3076	4008	cmd.exe	83
PID 4008 wrote to memory of 3076	4008	cmd.exe	83
PID 4008 wrote to memory of 3076	4008	cmd.exe	83

C:\Users\Admin\AppData\Local\Temp\542f3ea693d61187bd10db0376a6b3e7.exe
"C:\Users\Admin\AppData\Local\Temp\542f3ea693d61187bd10db0376a6b3e7.exe"
1⤵
- Adds Run key to start application
- Suspicious use of SetThreadContext
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:2008
- C:\Users\Admin\AppData\Local\Temp\542f3ea693d61187bd10db0376a6b3e7.exe
  C:\Users\Admin\AppData\Local\Temp\542f3ea693d61187bd10db0376a6b3e7.exe
  2⤵
  PID:2596
- C:\Users\Admin\AppData\Local\Temp\542f3ea693d61187bd10db0376a6b3e7.exe
  C:\Users\Admin\AppData\Local\Temp\542f3ea693d61187bd10db0376a6b3e7.exe
  2⤵
  - Loads dropped DLL
  - Checks processor information in registry
  - Suspicious use of WriteProcessMemory
  PID:4000
- - C:\Windows\SysWOW64\cmd.exe
    "C:\Windows\System32\cmd.exe" /c taskkill /pid 4000 & erase C:\Users\Admin\AppData\Local\Temp\542f3ea693d61187bd10db0376a6b3e7.exe & RD /S /Q C:\\ProgramData\\461124763642127\\* & exit
    3⤵
    - Suspicious use of WriteProcessMemory
    PID:4008
  - - C:\Windows\SysWOW64\taskkill.exe
      taskkill /pid 4000
      4⤵
      Kills process with taskkill
      Suspicious use of AdjustPrivilegeToken
      PID:3076