quasar | ba81b05c43bae8ee850ebff1ca399808b4828e5455ad2b2f9e64dd7962c33862

Analysis

max time kernel
125s
max time network
135s
platform
windows7_x64
resource
win7-20240221-en
resource tags

arch:x64arch:x86image:win7-20240221-enlocale:en-usos:windows7-x64system
submitted
01-07-2024 01:57

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General

Target

ba81b05c43bae8ee850ebff1ca399808b4828e5455ad2b2f9e64dd7962c33862.exe
Size

3.1MB
MD5

1633db1ce0d5eae8b246019541b00372
SHA1

00b8f4ede2ca86fd53b3012e4a317318a20dd39b
SHA256

ba81b05c43bae8ee850ebff1ca399808b4828e5455ad2b2f9e64dd7962c33862
SHA512

3843b4ad7b2a6d7dd8220f4dd30952a3f6d9918c1391234d3fc2abfcd2adcfd33a6d161a9ad562df661149dedaf5b0589484eb053fdb35c3f41983066e22751a
SSDEEP

49152:rvzlL26AaNeWgPhlmVqvMQ7XSKY9BSPnaMYLowdseTHHB72eh2NT:rvpL26AaNeWgPhlmVqkQ7XSK+oPY

Score

10^/10

quasar office04 spyware trojan

Malware Config

Extracted

Family

quasar

Version

1.4.1

Botnet

Office04

192.168.1.111:4782

Mutex

1f5e43b0-2e6e-4529-bedf-628650591bdf

Attributes

encryption_key
0FF1E4E83CF341CB74C4BB8B5D7980A41A9AF65B
install_name
DescryptMain.exe
log_directory
Logs
reconnect_delay
3000
startup_key
Quasar Client Startup
subdirectory
SubDir

Signatures

Quasar RAT
Quasar is an open source Remote Access Tool.
trojan spyware quasar

Quasar payload 3 IoCs

Processes:

resource	yara_rule
behavioral1/memory/1688-1-0x0000000000E70000-0x0000000001194000-memory.dmp	family_quasar
C:\Users\Admin\AppData\Roaming\SubDir\DescryptMain.exe	family_quasar
behavioral1/memory/2544-10-0x0000000000230000-0x0000000000554000-memory.dmp	family_quasar

Detects Windows executables referencing non-Windows User-Agents 3 IoCs

Processes:

resource	yara_rule
behavioral1/memory/1688-1-0x0000000000E70000-0x0000000001194000-memory.dmp	INDICATOR_SUSPICIOUS_EXE_NoneWindowsUA
C:\Users\Admin\AppData\Roaming\SubDir\DescryptMain.exe	INDICATOR_SUSPICIOUS_EXE_NoneWindowsUA
behavioral1/memory/2544-10-0x0000000000230000-0x0000000000554000-memory.dmp	INDICATOR_SUSPICIOUS_EXE_NoneWindowsUA

Detects binaries (Windows and macOS) referencing many web browsers. Observed in information stealers. 3 IoCs

Processes:

resource	yara_rule
behavioral1/memory/1688-1-0x0000000000E70000-0x0000000001194000-memory.dmp	INDICATOR_SUSPICIOUS_Binary_References_Browsers
C:\Users\Admin\AppData\Roaming\SubDir\DescryptMain.exe	INDICATOR_SUSPICIOUS_Binary_References_Browsers
behavioral1/memory/2544-10-0x0000000000230000-0x0000000000554000-memory.dmp	INDICATOR_SUSPICIOUS_Binary_References_Browsers

Detects executables containing common artifacts observed in infostealers 3 IoCs

Processes:

resource	yara_rule
behavioral1/memory/1688-1-0x0000000000E70000-0x0000000001194000-memory.dmp	INDICATOR_SUSPICIOUS_GENInfoStealer
C:\Users\Admin\AppData\Roaming\SubDir\DescryptMain.exe	INDICATOR_SUSPICIOUS_GENInfoStealer
behavioral1/memory/2544-10-0x0000000000230000-0x0000000000554000-memory.dmp	INDICATOR_SUSPICIOUS_GENInfoStealer

Executes dropped EXE 1 IoCs

Processes:

DescryptMain.exe

pid process

2544 DescryptMain.exe
Scheduled Task/Job: Scheduled Task 1 TTPs 2 IoCs
Schtasks is often used by malware for persistence or to perform post-infection execution.
persistence execution

Scheduled Task
T1053.005

Processes:

schtasks.exeschtasks.exe

pid process

2728 schtasks.exe
2976 schtasks.exe
Suspicious use of AdjustPrivilegeToken 2 IoCs

Processes:

ba81b05c43bae8ee850ebff1ca399808b4828e5455ad2b2f9e64dd7962c33862.exeDescryptMain.exe

description pid process

Token: SeDebugPrivilege 1688 ba81b05c43bae8ee850ebff1ca399808b4828e5455ad2b2f9e64dd7962c33862.exe
Token: SeDebugPrivilege 2544 DescryptMain.exe
Suspicious use of SetWindowsHookEx 1 IoCs

Processes:

DescryptMain.exe

pid process

2544 DescryptMain.exe

pid	process
2544	DescryptMain.exe

pid	process
2728	schtasks.exe
2976	schtasks.exe

description	pid	process
Token: SeDebugPrivilege	1688	ba81b05c43bae8ee850ebff1ca399808b4828e5455ad2b2f9e64dd7962c33862.exe
Token: SeDebugPrivilege	2544	DescryptMain.exe

pid	process
2544	DescryptMain.exe

Suspicious use of WriteProcessMemory 9 IoCs

Processes:

ba81b05c43bae8ee850ebff1ca399808b4828e5455ad2b2f9e64dd7962c33862.exeDescryptMain.exe

description	pid	process	target process
PID 1688 wrote to memory of 2728	1688	ba81b05c43bae8ee850ebff1ca399808b4828e5455ad2b2f9e64dd7962c33862.exe	schtasks.exe
PID 1688 wrote to memory of 2728	1688	ba81b05c43bae8ee850ebff1ca399808b4828e5455ad2b2f9e64dd7962c33862.exe	schtasks.exe
PID 1688 wrote to memory of 2728	1688	ba81b05c43bae8ee850ebff1ca399808b4828e5455ad2b2f9e64dd7962c33862.exe	schtasks.exe
PID 1688 wrote to memory of 2544	1688	ba81b05c43bae8ee850ebff1ca399808b4828e5455ad2b2f9e64dd7962c33862.exe	DescryptMain.exe
PID 1688 wrote to memory of 2544	1688	ba81b05c43bae8ee850ebff1ca399808b4828e5455ad2b2f9e64dd7962c33862.exe	DescryptMain.exe
PID 1688 wrote to memory of 2544	1688	ba81b05c43bae8ee850ebff1ca399808b4828e5455ad2b2f9e64dd7962c33862.exe	DescryptMain.exe
PID 2544 wrote to memory of 2976	2544	DescryptMain.exe	schtasks.exe
PID 2544 wrote to memory of 2976	2544	DescryptMain.exe	schtasks.exe
PID 2544 wrote to memory of 2976	2544	DescryptMain.exe	schtasks.exe

Uses Task Scheduler COM API 1 TTPs
The Task Scheduler COM API can be used to schedule applications to run on boot or at set times.
persistence

Query Registry
T1012

C:\Users\Admin\AppData\Local\Temp\ba81b05c43bae8ee850ebff1ca399808b4828e5455ad2b2f9e64dd7962c33862.exe
"C:\Users\Admin\AppData\Local\Temp\ba81b05c43bae8ee850ebff1ca399808b4828e5455ad2b2f9e64dd7962c33862.exe"
1⤵
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:1688

C:\Windows\system32\schtasks.exe
"schtasks" /create /tn "Quasar Client Startup" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\SubDir\DescryptMain.exe" /rl HIGHEST /f
2⤵
- Scheduled Task/Job: Scheduled Task
PID:2728

C:\Users\Admin\AppData\Roaming\SubDir\DescryptMain.exe
"C:\Users\Admin\AppData\Roaming\SubDir\DescryptMain.exe"
2⤵
- Executes dropped EXE
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of SetWindowsHookEx
- Suspicious use of WriteProcessMemory
PID:2544

C:\Windows\system32\schtasks.exe
"schtasks" /create /tn "Quasar Client Startup" /sc ONLOGON /tr "C:\Users\Admin\AppData\Roaming\SubDir\DescryptMain.exe" /rl HIGHEST /f
3⤵
- Scheduled Task/Job: Scheduled Task
PID:2976

Network

MITRE ATT&CK Matrix ATT&CK v13

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Downloads

C:\Users\Admin\AppData\Roaming\SubDir\DescryptMain.exe
Filesize
3.1MB

MD5
1633db1ce0d5eae8b246019541b00372

SHA1
00b8f4ede2ca86fd53b3012e4a317318a20dd39b

SHA256
ba81b05c43bae8ee850ebff1ca399808b4828e5455ad2b2f9e64dd7962c33862

SHA512
3843b4ad7b2a6d7dd8220f4dd30952a3f6d9918c1391234d3fc2abfcd2adcfd33a6d161a9ad562df661149dedaf5b0589484eb053fdb35c3f41983066e22751a

Download Submit
memory/1688-0-0x000007FEF51A3000-0x000007FEF51A4000-memory.dmp

Filesize
4KB

Download
memory/1688-1-0x0000000000E70000-0x0000000001194000-memory.dmp

Filesize
3.1MB

Download
memory/1688-2-0x000007FEF51A0000-0x000007FEF5B8C000-memory.dmp

Filesize
9.9MB

Download
memory/1688-9-0x000007FEF51A0000-0x000007FEF5B8C000-memory.dmp

Filesize
9.9MB

Download
memory/2544-8-0x000007FEF51A0000-0x000007FEF5B8C000-memory.dmp

Filesize
9.9MB

Download
memory/2544-10-0x0000000000230000-0x0000000000554000-memory.dmp

Filesize
3.1MB

Download
memory/2544-11-0x000007FEF51A0000-0x000007FEF5B8C000-memory.dmp

Filesize
9.9MB

Download
memory/2544-12-0x000007FEF51A0000-0x000007FEF5B8C000-memory.dmp

Filesize
9.9MB

Download