asyncrat | 7559e6ca8b77400f88bf4e67208a1c32570a670068eccae9e3d226cc5471bd47

Resubmissions

20-09-2024 07:43

240920-jkdj5avhqa 10

16-09-2024 13:49

240916-q4rz7a1apg 10

Analysis

max time kernel
147s
max time network
152s
platform
windows10-2004_x64
resource
win10v2004-20240802-en
resource tags

arch:x64arch:x86image:win10v2004-20240802-enlocale:en-usos:windows10-2004-x64system
submitted
16-09-2024 13:49

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General

Target

bazaar.2020.02/HEUR-Backdoor.MSIL.Crysan.exe
Size

46KB
MD5

b36ed4b297c327eb67746e85fe4434f4
SHA1

7f24843a465e1e811b82a79ced5b071f7350155b
SHA256

0a276fdaf3367ca3fd4cf90eb338dd3d0575ba3979f1bd609ce58e13e2aa0a8e
SHA512

d7002fcabec0e34f5200df23e1ba2b9b840ed502f7b22da9c231613092aa853d8fa1b76b6e934947c13ffbfab5ba49be1c057944c726f9b9cb565470c22c2cbf
SSDEEP

768:YCqJlzbXvMdSXekOicvHk3eHlWMPbPgF0qV1ZGF4G1Pc1pBSDHLw5YI6OC22tYch:YCjCeXvZH0ub4Fr/ZUdW1/uHL06O7Kme

Score

10^/10

asyncrat null rat

Malware Config

Extracted

Family

asyncrat

Version

0.5.6A

Botnet

null

bomi.duckdns.org:8080

Mutex

hutqlynrbwzq

Attributes

delay
5
install
true
install_file
Boomi.exe
install_folder
%AppData%

aes.plain

Signatures

AsyncRat
AsyncRAT is designed to remotely monitor and control other computers written in C#.
rat asyncrat

Checks computer location settings 2 TTPs 1 IoCs

Looks up country code configured in the registry, likely geofence.

Query Registry

T1012

System Information Discovery

T1082

description	ioc	Process
Key value queried	\REGISTRY\USER\S-1-5-21-2412658365-3084825385-3340777666-1000\Control Panel\International\Geo\Nation	HEUR-Backdoor.MSIL.Crysan.exe

Executes dropped EXE 1 IoCs

pid	Process
2020	Boomi.exe

Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s).

System Information Discovery
T1082

Delays execution with timeout.exe 1 IoCs

evasion

pid	Process
3244	timeout.exe

Scheduled Task/Job: Scheduled Task 1 TTPs 1 IoCs

Schtasks is often used by malware for persistence or to perform post-infection execution.

persistence execution

Scheduled Task

T1053.005

pid	Process
4044	schtasks.exe

Suspicious behavior: EnumeratesProcesses 24 IoCs

pid	Process
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
4728	HEUR-Backdoor.MSIL.Crysan.exe
2020	Boomi.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	4728	HEUR-Backdoor.MSIL.Crysan.exe
Token: SeDebugPrivilege	2020	Boomi.exe

Suspicious use of WriteProcessMemory 8 IoCs

description	pid	Process	procid_target
PID 4728 wrote to memory of 4044	4728	HEUR-Backdoor.MSIL.Crysan.exe	88
PID 4728 wrote to memory of 4044	4728	HEUR-Backdoor.MSIL.Crysan.exe	88
PID 4728 wrote to memory of 1724	4728	HEUR-Backdoor.MSIL.Crysan.exe	90
PID 4728 wrote to memory of 1724	4728	HEUR-Backdoor.MSIL.Crysan.exe	90
PID 1724 wrote to memory of 3244	1724	cmd.exe	92
PID 1724 wrote to memory of 3244	1724	cmd.exe	92
PID 1724 wrote to memory of 2020	1724	cmd.exe	93
PID 1724 wrote to memory of 2020	1724	cmd.exe	93

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\bazaar.2020.02\HEUR-Backdoor.MSIL.Crysan.exe
"C:\Users\Admin\AppData\Local\Temp\bazaar.2020.02\HEUR-Backdoor.MSIL.Crysan.exe"
1⤵
- Checks computer location settings
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:4728
- C:\Windows\System32\schtasks.exe
  "C:\Windows\System32\schtasks.exe" /create /f /sc ONLOGON /RL HIGHEST /tn "'Boomi"' /tr "'C:\Users\Admin\AppData\Roaming\Boomi.exe"'
  2⤵
  - Scheduled Task/Job: Scheduled Task
  PID:4044
- C:\Windows\system32\cmd.exe
  C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\tmpC9B8.tmp.bat""
  2⤵
  - Suspicious use of WriteProcessMemory
  PID:1724
- - C:\Windows\system32\timeout.exe
    timeout 3
    3⤵
    - Delays execution with timeout.exe
    PID:3244
- - C:\Users\Admin\AppData\Roaming\Boomi.exe
    "C:\Users\Admin\AppData\Roaming\Boomi.exe"
    3⤵
    - Executes dropped EXE
    - Suspicious behavior: EnumeratesProcesses
    - Suspicious use of AdjustPrivilegeToken
    PID:2020

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Scheduled Task/Job

T1053

Scheduled Task

T1053.005

Persistence

Scheduled Task/Job

T1053

Scheduled Task

T1053.005

Privilege Escalation

Scheduled Task/Job

T1053

Scheduled Task

T1053.005

Defense Evasion

Credential Access

Discovery

Query Registry

T1012

System Information Discovery

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Replay Monitor

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Downloads

C:\Users\Admin\AppData\Local\Temp\tmpC9B8.tmp.bat

Filesize
149B

MD5
abe66fb1ad9667227773c60e86444a68

SHA1
f2653181d4a363d610b96f6ef19cd1a58f5bdcca

SHA256
b808f1f6972a4f2b104a7addfb5073a4bc1bbd21701188b192cc515ec593278c

SHA512
0ba1b5136eaf85d67f90efbd2f4b6c81e743a0e6bea1083ce867fafac386ca1c992002e84c2fe4d23eb8fbe7708790a5d80d0739883a1af5dc18ac6c981de313

Download Submit
C:\Users\Admin\AppData\Roaming\Boomi.exe

Filesize
44.1MB

MD5
f5f849f0c4166a7a5e7f4202d6b4dfd5

SHA1
0036e0b4c04cab8a26804eca3601cbde5dca30b9

SHA256
04eb676fa5d027c7c1a38f8f1aac1e5a7a966bb2fcefba93f9a21bd172129de6

SHA512
4f22fc2a6eee364dd78bce9acf929b810ed501d8fe18531db0e8a63498d9b70debb11ef16c053808bf55f635ba9b2ba199a0bfe86d9067fdd814c1b8d4121ce1

Download Submit
memory/2020-14-0x00007FF8871F0000-0x00007FF887CB1000-memory.dmp

Filesize
10.8MB

Download
memory/2020-15-0x00007FF8871F0000-0x00007FF887CB1000-memory.dmp

Filesize
10.8MB

Download
memory/4728-0-0x00007FF8871F3000-0x00007FF8871F5000-memory.dmp

Filesize
8KB

Download
memory/4728-1-0x0000000000040000-0x0000000000052000-memory.dmp

Filesize
72KB

Download
memory/4728-2-0x00007FF8871F0000-0x00007FF887CB1000-memory.dmp

Filesize
10.8MB

Download
memory/4728-3-0x00007FF8871F3000-0x00007FF8871F5000-memory.dmp

Filesize
8KB

Download
memory/4728-4-0x00007FF8871F0000-0x00007FF887CB1000-memory.dmp

Filesize
10.8MB

Download
memory/4728-10-0x00007FF8871F0000-0x00007FF887CB1000-memory.dmp

Filesize
10.8MB

Download