oski | c87ec3f9dfb87a10f1c38102a3c58bc2cbb252891b5c882f3c4f3f0a9058b170

General

Target

gunzipped.exe
Size

730KB
MD5

02c69e67c2f23c547d0022147da9fbe9
SHA1

6686b9d64df9a2c31f61c5a6682b2d899ab1a599
SHA256

c87ec3f9dfb87a10f1c38102a3c58bc2cbb252891b5c882f3c4f3f0a9058b170
SHA512

7fcd69e6b1eb521200d7111ff120f9fb2b67ff76f3bb49372781a9469224831ca21aad0955e1b72bd98d677450c8726053601b703818a8573e4cded9b3950c73

Score

10^/10

oski discovery infostealer spyware stealer

Malware Config

Extracted

Family

oski

C2

master101work.co

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

1976 cmd.exe
Loads dropped DLL 3 IoCs

Processes:

gunzipped.exe

pid process

1636 gunzipped.exe
1636 gunzipped.exe
1636 gunzipped.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:

gunzipped.exe

description pid process target process

PID 2012 set thread context of 1636 2012 gunzipped.exe gunzipped.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:

gunzipped.exe

description ioc process

Key value queried \REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0\ProcessorNameString gunzipped.exe
Creates scheduled task(s) 1 TTPs 1 IoCs
Schtasks is often used by malware for persistence or to perform post-infection execution.
persistence

Scheduled Task
T1053

Processes:

schtasks.exe

pid process

1452 schtasks.exe
Kills process with taskkill 1 IoCs
evasion

Processes:

taskkill.exe

pid process

996 taskkill.exe
Suspicious behavior: EnumeratesProcesses 1 IoCs

Processes:

powershell.exe

pid process

1144 powershell.exe
Suspicious use of AdjustPrivilegeToken 2 IoCs

Processes:

powershell.exetaskkill.exe

description pid process

Token: SeDebugPrivilege 1144 powershell.exe
Token: SeDebugPrivilege 996 taskkill.exe

pid	process
1976	cmd.exe

pid	process
1636	gunzipped.exe
1636	gunzipped.exe
1636	gunzipped.exe

description	pid	process	target process
PID 2012 set thread context of 1636	2012	gunzipped.exe	gunzipped.exe

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

pid	process
1452	schtasks.exe

pid	process
996	taskkill.exe

pid	process
1144	powershell.exe

description	pid	process
Token: SeDebugPrivilege	1144	powershell.exe
Token: SeDebugPrivilege	996	taskkill.exe

Suspicious use of WriteProcessMemory 26 IoCs

Processes:

gunzipped.exegunzipped.execmd.exe

description	pid	process	target process
PID 2012 wrote to memory of 1144	2012	gunzipped.exe	powershell.exe
PID 2012 wrote to memory of 1144	2012	gunzipped.exe	powershell.exe
PID 2012 wrote to memory of 1144	2012	gunzipped.exe	powershell.exe
PID 2012 wrote to memory of 1144	2012	gunzipped.exe	powershell.exe
PID 2012 wrote to memory of 1452	2012	gunzipped.exe	schtasks.exe
PID 2012 wrote to memory of 1452	2012	gunzipped.exe	schtasks.exe
PID 2012 wrote to memory of 1452	2012	gunzipped.exe	schtasks.exe
PID 2012 wrote to memory of 1452	2012	gunzipped.exe	schtasks.exe
PID 2012 wrote to memory of 1636	2012	gunzipped.exe	gunzipped.exe
PID 2012 wrote to memory of 1636	2012	gunzipped.exe	gunzipped.exe
PID 2012 wrote to memory of 1636	2012	gunzipped.exe	gunzipped.exe
PID 2012 wrote to memory of 1636	2012	gunzipped.exe	gunzipped.exe
PID 2012 wrote to memory of 1636	2012	gunzipped.exe	gunzipped.exe
PID 2012 wrote to memory of 1636	2012	gunzipped.exe	gunzipped.exe
PID 2012 wrote to memory of 1636	2012	gunzipped.exe	gunzipped.exe
PID 2012 wrote to memory of 1636	2012	gunzipped.exe	gunzipped.exe
PID 2012 wrote to memory of 1636	2012	gunzipped.exe	gunzipped.exe
PID 2012 wrote to memory of 1636	2012	gunzipped.exe	gunzipped.exe
PID 1636 wrote to memory of 1976	1636	gunzipped.exe	cmd.exe
PID 1636 wrote to memory of 1976	1636	gunzipped.exe	cmd.exe
PID 1636 wrote to memory of 1976	1636	gunzipped.exe	cmd.exe
PID 1636 wrote to memory of 1976	1636	gunzipped.exe	cmd.exe
PID 1976 wrote to memory of 996	1976	cmd.exe	taskkill.exe
PID 1976 wrote to memory of 996	1976	cmd.exe	taskkill.exe
PID 1976 wrote to memory of 996	1976	cmd.exe	taskkill.exe
PID 1976 wrote to memory of 996	1976	cmd.exe	taskkill.exe

C:\Users\Admin\AppData\Local\Temp\gunzipped.exe
"C:\Users\Admin\AppData\Local\Temp\gunzipped.exe"
1⤵
- Suspicious use of SetThreadContext
- Suspicious use of WriteProcessMemory
PID:2012

C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
"C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" Add-MpPreference -ExclusionPath "C:\Users\Admin\AppData\Roaming\yGkHpD.exe"
2⤵
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
PID:1144

C:\Windows\SysWOW64\schtasks.exe
"C:\Windows\System32\schtasks.exe" /Create /TN "Updates\yGkHpD" /XML "C:\Users\Admin\AppData\Local\Temp\tmpD0C8.tmp"
2⤵
- Creates scheduled task(s)
PID:1452

C:\Users\Admin\AppData\Local\Temp\gunzipped.exe
"C:\Users\Admin\AppData\Local\Temp\gunzipped.exe"
2⤵
- Loads dropped DLL
- Checks processor information in registry
- Suspicious use of WriteProcessMemory
PID:1636

C:\Windows\SysWOW64\cmd.exe
"C:\Windows\System32\cmd.exe" /c taskkill /pid 1636 & erase C:\Users\Admin\AppData\Local\Temp\gunzipped.exe & RD /S /Q C:\\ProgramData\\601599751069507\\* & exit
3⤵
- Deletes itself
- Suspicious use of WriteProcessMemory
PID:1976

C:\Windows\SysWOW64\taskkill.exe
taskkill /pid 1636
4⤵
- Kills process with taskkill
- Suspicious use of AdjustPrivilegeToken
PID:996

Network

MITRE ATT&CK Matrix ATT&CK v6

Initial Access

Execution

Scheduled Task

1

T1053

Persistence

Scheduled Task

1

T1053

Privilege Escalation

Scheduled Task

1

T1053

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

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Downloads

C:\Users\Admin\AppData\Local\Temp\tmpD0C8.tmp
Filesize
1KB

MD5
5b0a28aea2b1ff2de65e0d696ab2bc3b

SHA1
f2fc81090d9a86498c2e918ed0a765f199fdf79c

SHA256
71fc275d2f0e914b1b07251a119767fa60c63515018b68460832d9a6e764e7bf

SHA512
460562db973fc29da4fb1a1dc8bde3f5f3b2ab6a09b237a501000b1d3a58c3993ab0099a67521bd92eb6f0018bd62b3cb41570ec1c8229c74cb800896943db5c

Download Submit
\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/996-86-0x0000000000000000-mapping.dmp

Download
memory/1144-79-0x0000000074D60000-0x000000007530B000-memory.dmp

Filesize
5.7MB

Download
memory/1144-59-0x0000000000000000-mapping.dmp

Download
memory/1144-80-0x0000000074D60000-0x000000007530B000-memory.dmp

Filesize
5.7MB

Download
memory/1452-60-0x0000000000000000-mapping.dmp

Download
memory/1636-78-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/1636-71-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/1636-64-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/1636-69-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/1636-85-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/1636-73-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/1636-74-0x000000000040717B-mapping.dmp

Download
memory/1636-76-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/1636-67-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/1636-65-0x0000000000400000-0x0000000000438000-memory.dmp

Filesize
224KB

Download
memory/1976-84-0x0000000000000000-mapping.dmp

Download
memory/2012-54-0x0000000000A70000-0x0000000000B2C000-memory.dmp

Filesize
752KB

Download
memory/2012-58-0x0000000005CA0000-0x0000000005D28000-memory.dmp

Filesize
544KB

Download
memory/2012-57-0x0000000000A50000-0x0000000000A5A000-memory.dmp

Filesize
40KB

Download
memory/2012-56-0x00000000009F0000-0x0000000000A06000-memory.dmp

Filesize
88KB

Download
memory/2012-63-0x0000000005DA0000-0x0000000005DDC000-memory.dmp

Filesize
240KB

Download
memory/2012-55-0x0000000075791000-0x0000000075793000-memory.dmp

Filesize
8KB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Matrix ATT&CK v6

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