asyncrat | b6c58155365a5e35952e46611fd7b43e36e256903bff2030bc07a3c6841b836f

General

Target

AsyncClient.exe
Size

45KB
MD5

7ace559d317742937e8254dc6da92a7e
SHA1

e4986e5b11b96bedc62af5cfb3b48bed58d8d1c9
SHA256

b6c58155365a5e35952e46611fd7b43e36e256903bff2030bc07a3c6841b836f
SHA512

2c50337078075dc6bfd8b02d77d4de8e5b9ad5b01deed1a3b4f3eb0b2d21efce2736e74d5cf94fdf937bcc2a51c2ecf98022049c706350feacb079c4b968d5d3
SSDEEP

768:hukaVT3ongoWU2zjimo2qrrKjGKG6PIyzjbFgX3ij8z+vfYO4qHBDZMhd:hukaVT3QR2mKYDy3bCXSjlfYQdMd

Score

10^/10

asyncrat default discovery rat

Malware Config

Extracted

Family

asyncrat

Version

0.5.7B

Botnet

Default

C2

96.248.52.125:8031

Mutex

adobe_6SI8OkPnk

Attributes

delay
3
install
true
install_file
update.exe
install_folder
%Temp%

aes.plain

Signatures

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

Async RAT payload 1 IoCs

rat

resource	yara_rule
behavioral2/files/0x0008000000023cbf-11.dat	family_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-1-5-21-4050598569-1597076380-177084960-1000\Control Panel\International\Geo\Nation	AsyncClient.exe

Executes dropped EXE 1 IoCs

pid	Process
3892	update.exe

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

System Information Discovery
T1082

System Location Discovery: System Language Discovery 1 TTPs 6 IoCs

Attempt gather information about the system language of a victim in order to infer the geographical location of that host.

discovery

System Language Discovery

T1614.001

description	ioc	Process
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	cmd.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	cmd.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	schtasks.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	timeout.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	update.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	AsyncClient.exe

Delays execution with timeout.exe 1 IoCs

evasion

pid	Process
688	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
4388	schtasks.exe

Suspicious behavior: EnumeratesProcesses 23 IoCs

pid	Process
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe
1900	AsyncClient.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	1900	AsyncClient.exe
Token: SeDebugPrivilege	3892	update.exe

Suspicious use of WriteProcessMemory 15 IoCs

description	pid	Process	procid_target
PID 1900 wrote to memory of 3064	1900	AsyncClient.exe	82
PID 1900 wrote to memory of 3064	1900	AsyncClient.exe	82
PID 1900 wrote to memory of 3064	1900	AsyncClient.exe	82
PID 1900 wrote to memory of 4720	1900	AsyncClient.exe	84
PID 1900 wrote to memory of 4720	1900	AsyncClient.exe	84
PID 1900 wrote to memory of 4720	1900	AsyncClient.exe	84
PID 3064 wrote to memory of 4388	3064	cmd.exe	86
PID 3064 wrote to memory of 4388	3064	cmd.exe	86
PID 3064 wrote to memory of 4388	3064	cmd.exe	86
PID 4720 wrote to memory of 688	4720	cmd.exe	87
PID 4720 wrote to memory of 688	4720	cmd.exe	87
PID 4720 wrote to memory of 688	4720	cmd.exe	87
PID 4720 wrote to memory of 3892	4720	cmd.exe	92
PID 4720 wrote to memory of 3892	4720	cmd.exe	92
PID 4720 wrote to memory of 3892	4720	cmd.exe	92

C:\Users\Admin\AppData\Local\Temp\AsyncClient.exe
"C:\Users\Admin\AppData\Local\Temp\AsyncClient.exe"
1⤵
- Checks computer location settings
- System Location Discovery: System Language Discovery
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:1900
- C:\Windows\SysWOW64\cmd.exe
  "C:\Windows\System32\cmd.exe" /c schtasks /create /f /sc onlogon /rl highest /tn "update" /tr '"C:\Users\Admin\AppData\Local\Temp\update.exe"' & exit
  2⤵
  - System Location Discovery: System Language Discovery
  - Suspicious use of WriteProcessMemory
  PID:3064
- - C:\Windows\SysWOW64\schtasks.exe
    schtasks /create /f /sc onlogon /rl highest /tn "update" /tr '"C:\Users\Admin\AppData\Local\Temp\update.exe"'
    3⤵
    - System Location Discovery: System Language Discovery
    - Scheduled Task/Job: Scheduled Task
    PID:4388
- C:\Windows\SysWOW64\cmd.exe
  C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\tmpC6DA.tmp.bat""
  2⤵
  - System Location Discovery: System Language Discovery
  - Suspicious use of WriteProcessMemory
  PID:4720
- - C:\Windows\SysWOW64\timeout.exe
    timeout 3
    3⤵
    - System Location Discovery: System Language Discovery
    - Delays execution with timeout.exe
    PID:688
- - C:\Users\Admin\AppData\Local\Temp\update.exe
    "C:\Users\Admin\AppData\Local\Temp\update.exe"
    3⤵
    - Executes dropped EXE
    - System Location Discovery: System Language Discovery
    - Suspicious use of AdjustPrivilegeToken
    PID:3892

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Persistence

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Privilege Escalation

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Defense Evasion

Credential Access

Discovery

Query Registry

1

T1012

System Information Discovery

2

T1082

System Location Discovery

1

T1614

System Language Discovery

1

T1614.001

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Replay Monitor

Loading Replay Monitor...

Downloads

C:\Users\Admin\AppData\Local\Temp\tmpC6DA.tmp.bat

Filesize
153B

MD5
3386b05ed7b289ddf73ed728de850ab6

SHA1
e3500d81a0571ec67843c10a13dbe64e2129f29a

SHA256
544b2d7e64242cf5826ae2afdf45e8238bebaf563d5b9352f33427ca158bc695

SHA512
546a2999cce3727a9811070fae5797072fe8189d323262f7dcdcee2b2997c601973a139debc68311a73d8dd8aa32b99b0915c0f1c01ebc09c5ed8ca517ed2c05

Download Submit
C:\Users\Admin\AppData\Local\Temp\update.exe

Filesize
45KB

MD5
7ace559d317742937e8254dc6da92a7e

SHA1
e4986e5b11b96bedc62af5cfb3b48bed58d8d1c9

SHA256
b6c58155365a5e35952e46611fd7b43e36e256903bff2030bc07a3c6841b836f

SHA512
2c50337078075dc6bfd8b02d77d4de8e5b9ad5b01deed1a3b4f3eb0b2d21efce2736e74d5cf94fdf937bcc2a51c2ecf98022049c706350feacb079c4b968d5d3

Download Submit
memory/1900-0-0x0000000074F6E000-0x0000000074F6F000-memory.dmp

Filesize
4KB

Download
memory/1900-1-0x00000000006F0000-0x0000000000702000-memory.dmp

Filesize
72KB

Download
memory/1900-2-0x0000000074F60000-0x0000000075710000-memory.dmp

Filesize
7.7MB

Download
memory/1900-3-0x00000000050C0000-0x000000000515C000-memory.dmp

Filesize
624KB

Download
memory/1900-8-0x0000000074F60000-0x0000000075710000-memory.dmp

Filesize
7.7MB

Download
memory/3892-13-0x0000000074EB0000-0x0000000075660000-memory.dmp

Filesize
7.7MB

Download
memory/3892-14-0x0000000074EB0000-0x0000000075660000-memory.dmp

Filesize
7.7MB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

Replay Monitor

Loading Replay Monitor...

Downloads