oski | 244cc88debf6465b93584d1f63c592c52bd029deec2f24fc4a3328725838d239

General

Target

PO5621.scr.exe
Size

306KB
MD5

b0926a6e4c1887f81024b17df73199c5
SHA1

3fcdd6ff8323713c8cf3e11edca6c5e195dd4139
SHA256

244cc88debf6465b93584d1f63c592c52bd029deec2f24fc4a3328725838d239
SHA512

b16dd1c26ce8c4654202a9ca779f3a2ce12a563a5b7670e06610829d2b1abd092543a524247ed7997d56f26bb1d02b5c6310eb12a5a741260ab298fb5d61f1f8

Score

10^/10

oski discovery infostealer spyware stealer

Malware Config

Extracted

Family

oski

C2

203.159.80.65

Signatures

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

Deletes itself 1 IoCs

pid	Process
1484	cmd.exe

Loads dropped DLL 6 IoCs

pid	Process
1096	PO5621.scr.exe
1200	PO5621.scr.exe
1200	PO5621.scr.exe
1200	PO5621.scr.exe
1200	PO5621.scr.exe
1200	PO5621.scr.exe

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
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 1096 set thread context of 1200	1096	PO5621.scr.exe	26

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

description	ioc	Process
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0\ProcessorNameString	PO5621.scr.exe

Kills process with taskkill 1 IoCs

evasion

pid	Process
876	taskkill.exe

Suspicious behavior: MapViewOfSection 1 IoCs

pid	Process
1096	PO5621.scr.exe

Suspicious use of AdjustPrivilegeToken 1 IoCs

description	pid	Process
Token: SeDebugPrivilege	876	taskkill.exe

Suspicious use of WriteProcessMemory 13 IoCs

description	pid	Process	procid_target
PID 1096 wrote to memory of 1200	1096	PO5621.scr.exe	26
PID 1096 wrote to memory of 1200	1096	PO5621.scr.exe	26
PID 1096 wrote to memory of 1200	1096	PO5621.scr.exe	26
PID 1096 wrote to memory of 1200	1096	PO5621.scr.exe	26
PID 1096 wrote to memory of 1200	1096	PO5621.scr.exe	26
PID 1200 wrote to memory of 1484	1200	PO5621.scr.exe	32
PID 1200 wrote to memory of 1484	1200	PO5621.scr.exe	32
PID 1200 wrote to memory of 1484	1200	PO5621.scr.exe	32
PID 1200 wrote to memory of 1484	1200	PO5621.scr.exe	32
PID 1484 wrote to memory of 876	1484	cmd.exe	34
PID 1484 wrote to memory of 876	1484	cmd.exe	34
PID 1484 wrote to memory of 876	1484	cmd.exe	34
PID 1484 wrote to memory of 876	1484	cmd.exe	34

C:\Users\Admin\AppData\Local\Temp\PO5621.scr.exe
"C:\Users\Admin\AppData\Local\Temp\PO5621.scr.exe"
1⤵
- Loads dropped DLL
- Suspicious use of SetThreadContext
- Suspicious behavior: MapViewOfSection
- Suspicious use of WriteProcessMemory
PID:1096
- C:\Users\Admin\AppData\Local\Temp\PO5621.scr.exe
  "C:\Users\Admin\AppData\Local\Temp\PO5621.scr.exe"
  2⤵
  - Loads dropped DLL
  - Checks processor information in registry
  - Suspicious use of WriteProcessMemory
  PID:1200
- - C:\Windows\SysWOW64\cmd.exe
    "C:\Windows\System32\cmd.exe" /c taskkill /pid 1200 & erase C:\Users\Admin\AppData\Local\Temp\PO5621.scr.exe & RD /S /Q C:\\ProgramData\\546498067793251\\* & exit
    3⤵
    - Deletes itself
    - Suspicious use of WriteProcessMemory
    PID:1484
  - - C:\Windows\SysWOW64\taskkill.exe
      taskkill /pid 1200
      4⤵
      Kills process with taskkill
      Suspicious use of AdjustPrivilegeToken
      PID:876

Network

MITRE ATT&CK Enterprise v6

Initial Access

Execution

Persistence

Privilege Escalation

Defense Evasion

Credential Access

Credentials in Files

2

T1081

Discovery

Query Registry

2

T1012

System Information Discovery

2

T1082

Lateral Movement

Collection

Data from Local System

2

T1005

Command and Control

Exfiltration

Impact

Replay Monitor

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Downloads

memory/1096-60-0x0000000075281000-0x0000000075283000-memory.dmp

Filesize
8KB

Download
memory/1096-64-0x00000000003C0000-0x00000000003C2000-memory.dmp

Filesize
8KB

Download
memory/1200-65-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download

Analysis

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