oski | afdbf26cb55fb5d7acb13eee328ced4ffd4fd1d42a72dc95fb1053b264ec45ee

General

Target

Ybhfk.exe
Size

685KB
MD5

4087a6277a5288c9dfddee6b28895c0f
SHA1

21b5e3b09c99c6da44219e53dbbe02e3c155c53a
SHA256

afdbf26cb55fb5d7acb13eee328ced4ffd4fd1d42a72dc95fb1053b264ec45ee
SHA512

a9b0ce9bdb3fb683fadf5947efad71c66d0de9e2f5f680c78e98ac48ab6c47967f213c5bff880798f90f236612817e09b3519493d3fece6f66497c37469a56c8

Score

10^/10

oski discovery infostealer spyware stealer

Malware Config

Extracted

Family

oski

C2

209.141.40.19

Signatures

Oski
Oski is an infostealer targeting browser data, crypto wallets.
infostealer oski
Downloads MZ/PE file
Deletes itself 1 IoCs

Processes:

cmd.exe

pid process

1544 cmd.exe
Loads dropped DLL 5 IoCs

Processes:

Ybhfk.exe

pid process

304 Ybhfk.exe
304 Ybhfk.exe
304 Ybhfk.exe
304 Ybhfk.exe
304 Ybhfk.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

Processes:

Ybhfk.exe

description pid process target process

PID 1996 set thread context of 304 1996 Ybhfk.exe Ybhfk.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:

Ybhfk.exe

description ioc process

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

Processes:

taskkill.exe

pid process

1804 taskkill.exe
Suspicious behavior: EnumeratesProcesses 1 IoCs

Processes:

Ybhfk.exe

pid process

1996 Ybhfk.exe
Suspicious use of AdjustPrivilegeToken 2 IoCs

Processes:

Ybhfk.exetaskkill.exe

description pid process

Token: SeDebugPrivilege 1996 Ybhfk.exe
Token: SeDebugPrivilege 1804 taskkill.exe

pid	process
1544	cmd.exe

pid	process
304	Ybhfk.exe
304	Ybhfk.exe
304	Ybhfk.exe
304	Ybhfk.exe
304	Ybhfk.exe

description	pid	process	target process
PID 1996 set thread context of 304	1996	Ybhfk.exe	Ybhfk.exe

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

pid	process
1804	taskkill.exe

pid	process
1996	Ybhfk.exe

description	pid	process
Token: SeDebugPrivilege	1996	Ybhfk.exe
Token: SeDebugPrivilege	1804	taskkill.exe

Suspicious use of WriteProcessMemory 18 IoCs

Processes:

Ybhfk.exeYbhfk.execmd.exe

description	pid	process	target process
PID 1996 wrote to memory of 304	1996	Ybhfk.exe	Ybhfk.exe
PID 1996 wrote to memory of 304	1996	Ybhfk.exe	Ybhfk.exe
PID 1996 wrote to memory of 304	1996	Ybhfk.exe	Ybhfk.exe
PID 1996 wrote to memory of 304	1996	Ybhfk.exe	Ybhfk.exe
PID 1996 wrote to memory of 304	1996	Ybhfk.exe	Ybhfk.exe
PID 1996 wrote to memory of 304	1996	Ybhfk.exe	Ybhfk.exe
PID 1996 wrote to memory of 304	1996	Ybhfk.exe	Ybhfk.exe
PID 1996 wrote to memory of 304	1996	Ybhfk.exe	Ybhfk.exe
PID 1996 wrote to memory of 304	1996	Ybhfk.exe	Ybhfk.exe
PID 1996 wrote to memory of 304	1996	Ybhfk.exe	Ybhfk.exe
PID 304 wrote to memory of 1544	304	Ybhfk.exe	cmd.exe
PID 304 wrote to memory of 1544	304	Ybhfk.exe	cmd.exe
PID 304 wrote to memory of 1544	304	Ybhfk.exe	cmd.exe
PID 304 wrote to memory of 1544	304	Ybhfk.exe	cmd.exe
PID 1544 wrote to memory of 1804	1544	cmd.exe	taskkill.exe
PID 1544 wrote to memory of 1804	1544	cmd.exe	taskkill.exe
PID 1544 wrote to memory of 1804	1544	cmd.exe	taskkill.exe
PID 1544 wrote to memory of 1804	1544	cmd.exe	taskkill.exe

C:\Users\Admin\AppData\Local\Temp\Ybhfk.exe
"C:\Users\Admin\AppData\Local\Temp\Ybhfk.exe"
1⤵
- Suspicious use of SetThreadContext
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:1996

C:\Users\Admin\AppData\Local\Temp\Ybhfk.exe
C:\Users\Admin\AppData\Local\Temp\Ybhfk.exe
2⤵
- Loads dropped DLL
- Checks processor information in registry
- Suspicious use of WriteProcessMemory
PID:304

C:\Windows\SysWOW64\cmd.exe
"C:\Windows\System32\cmd.exe" /c taskkill /pid 304 & erase C:\Users\Admin\AppData\Local\Temp\Ybhfk.exe & RD /S /Q C:\\ProgramData\\560605509043254\\* & exit
3⤵
- Deletes itself
- Suspicious use of WriteProcessMemory
PID:1544

C:\Windows\SysWOW64\taskkill.exe
taskkill /pid 304
4⤵
- Kills process with taskkill
- Suspicious use of AdjustPrivilegeToken
PID:1804

Network

MITRE ATT&CK Matrix ATT&CK 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

Exfiltration

Command and Control

Impact

Replay Monitor

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Downloads

\ProgramData\mozglue.dll
MD5
8f73c08a9660691143661bf7332c3c27

SHA1
37fa65dd737c50fda710fdbde89e51374d0c204a

SHA256
3fe6b1c54b8cf28f571e0c5d6636b4069a8ab00b4f11dd842cfec00691d0c9cd

SHA512
0042ecf9b3571bb5eba2de893e8b2371df18f7c5a589f52ee66e4bfbaa15a5b8b7cc6a155792aaa8988528c27196896d5e82e1751c998bacea0d92395f66ad89

Download Submit
\ProgramData\msvcp140.dll
MD5
109f0f02fd37c84bfc7508d4227d7ed5

SHA1
ef7420141bb15ac334d3964082361a460bfdb975

SHA256
334e69ac9367f708ce601a6f490ff227d6c20636da5222f148b25831d22e13d4

SHA512
46eb62b65817365c249b48863d894b4669e20fcb3992e747cd5c9fdd57968e1b2cf7418d1c9340a89865eadda362b8db51947eb4427412eb83b35994f932fd39

Download Submit
\ProgramData\nss3.dll
MD5
bfac4e3c5908856ba17d41edcd455a51

SHA1
8eec7e888767aa9e4cca8ff246eb2aacb9170428

SHA256
e2935b5b28550d47dc971f456d6961f20d1633b4892998750140e0eaa9ae9d78

SHA512
2565bab776c4d732ffb1f9b415992a4c65b81bcd644a9a1df1333a269e322925fc1df4f76913463296efd7c88ef194c3056de2f1ca1357d7b5fe5ff0da877a66

Download Submit
\ProgramData\sqlite3.dll
MD5
e477a96c8f2b18d6b5c27bde49c990bf

SHA1
e980c9bf41330d1e5bd04556db4646a0210f7409

SHA256
16574f51785b0e2fc29c2c61477eb47bb39f714829999511dc8952b43ab17660

SHA512
335a86268e7c0e568b1c30981ec644e6cd332e66f96d2551b58a82515316693c1859d87b4f4b7310cf1ac386cee671580fdd999c3bcb23acf2c2282c01c8798c

Download Submit
\ProgramData\vcruntime140.dll
MD5
7587bf9cb4147022cd5681b015183046

SHA1
f2106306a8f6f0da5afb7fc765cfa0757ad5a628

SHA256
c40bb03199a2054dabfc7a8e01d6098e91de7193619effbd0f142a7bf031c14d

SHA512
0b63e4979846ceba1b1ed8470432ea6aa18cca66b5f5322d17b14bc0dfa4b2ee09ca300a016e16a01db5123e4e022820698f46d9bad1078bd24675b4b181e91f

Download Submit
memory/304-67-0x00000000767B1000-0x00000000767B3000-memory.dmp

Filesize
8KB

Download
memory/304-68-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/304-65-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/304-66-0x000000000040717B-mapping.dmp

Download
memory/1544-74-0x0000000000000000-mapping.dmp

Download
memory/1804-75-0x0000000000000000-mapping.dmp

Download
memory/1996-60-0x0000000001050000-0x0000000001051000-memory.dmp

Filesize
4KB

Download
memory/1996-64-0x0000000000B00000-0x0000000000B1A000-memory.dmp

Filesize
104KB

Download
memory/1996-63-0x0000000000620000-0x0000000000698000-memory.dmp

Filesize
480KB

Download
memory/1996-62-0x0000000004B70000-0x0000000004B71000-memory.dmp

Filesize
4KB

Download

Analysis

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