asyncrat | 41d7d8d9eef7819dff69c2fe448c4333b9eeeb0d0f4bf86489521abb0ce58d63

General

Target
gayyy.exe
Size 47KB
Sample260728-ejmn7axfkh
SHA256 41d7d8d9eef7819dff69c2fe448c4333b9eeeb0d0f4bf86489521abb0ce58d63
MD5 de7e82e617be73ced59585f3dd73b38d
SHA1 7c06d9c7490bed6fe3756c256bdf840ff9242241
SHA512 7bc47849631b32b0ce7efd88ab2a2fc2d3454d448ea38961a0f311c1529146125d7adb3e3418a342fb530d9aecb146c4d71160f16bed3182a03b6ea235c825c1
SSDEEP 768:QuANNTR4ydbWUnrGJmo2q7V/mxZ20tlNPIVJDw1y0bQ6zwuVvE+LPZgQraBDZAx:QuANNTRZ22Q/r0t0VJkNbQ6FVvECPuQf
TLSH
T1E7232C007BE98236F2BE4F74A9F22155867AB2673603D64D2CC441D75A13FC29A426FE
MD5 SHA1 SHA512 SSDEEP TLSH

Score

10^/10

default defense_evasion discovery execution asyncrat persistence rat

Malware Config

Extracted

Family

asyncrat

Version

0.5.8

Botnet

Default

C2

789win.thaichi.co/vn/:6606
789win.thaichi.co/vn/:80
789win.thaichi.co/vn/:8080
789win.thaichi.co/vn/:443
789win.thaichi.co/vn/:8443
789win.thaichi.co/vn/:22
789win.thaichi.co/vn/:23
thaichi.co/vn/:6606
thaichi.co/vn/:80
thaichi.co/vn/:8080
thaichi.co/vn/:443
thaichi.co/vn/:8443
thaichi.co/vn/:22
thaichi.co/vn/:23

Mutex

09ESpI2azpOD

Attributes

delay
3
install
true
install_file
GoogleUpdate.exe
install_folder
%AppData%

aes.plain

Signatures

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

Async RAT payload 1 IoCs

rat

resource	yara_rule
behavioral1/files/0x0008000000024658-9.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-1-5-21-3053180483-1881419501-3594244048-1000\Control Panel\International\Geo\Nation	gayyy.exe

Executes dropped EXE 2 IoCs

pid	Process
4904	GoogleUpdate.exe
1976	GoogleUpdate.exe

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

System Information Discovery
T1082

Executes a command shell one-liner 1 TTPs 2 IoCs

Execution of a cmd.exe one-liner (/c "close" or /k "keep") is a common script/loader stage.

execution

Windows Command Shell

T1059.003

pid	Process
4432	cmd.exe
636	cmd.exe

System Location Discovery: System Language Discovery 1 TTPs 7 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	schtasks.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	GoogleUpdate.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	GoogleUpdate.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	gayyy.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	cmd.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	timeout.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	cmd.exe

Delays execution with timeout.exe 1 IoCs

defense_evasion

pid	Process
1256	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
1288	schtasks.exe

Suspicious behavior: EnumeratesProcesses 21 IoCs

pid	Process
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe
732	gayyy.exe

Suspicious use of AdjustPrivilegeToken 3 IoCs

description	pid	Process
Token: SeDebugPrivilege	732	gayyy.exe
Token: SeDebugPrivilege	4904	GoogleUpdate.exe
Token: SeDebugPrivilege	4904	GoogleUpdate.exe

Suspicious use of WriteProcessMemory 5 IoCs

description	pid	Process	procid_target
PID 732 wrote to memory of 4432	732	gayyy.exe	87
PID 732 wrote to memory of 636	732	gayyy.exe	89
PID 636 wrote to memory of 1256	636	cmd.exe	91
PID 4432 wrote to memory of 1288	4432	cmd.exe	92
PID 636 wrote to memory of 1976	636	cmd.exe	95

C:\Users\Admin\AppData\Local\Temp\gayyy.exe
"C:\Users\Admin\AppData\Local\Temp\gayyy.exe"
1⤵
- Checks computer location settings
- System Location Discovery: System Language Discovery
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:732
- C:\Windows\SysWOW64\cmd.exe
  "C:\Windows\System32\cmd.exe" /c schtasks /create /f /sc onlogon /rl highest /tn "GoogleUpdate" /tr '"C:\Users\Admin\AppData\Roaming\GoogleUpdate.exe"' & exit
  2⤵
  - Executes a command shell one-liner
  - System Location Discovery: System Language Discovery
  - Suspicious use of WriteProcessMemory
  PID:4432
- - C:\Windows\SysWOW64\schtasks.exe
    schtasks /create /f /sc onlogon /rl highest /tn "GoogleUpdate" /tr '"C:\Users\Admin\AppData\Roaming\GoogleUpdate.exe"'
    3⤵
    - System Location Discovery: System Language Discovery
    - Scheduled Task/Job: Scheduled Task
    PID:1288
- C:\Windows\SysWOW64\cmd.exe
  C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\tmp6A5D.tmp.bat""
  2⤵
  - Executes a command shell one-liner
  - System Location Discovery: System Language Discovery
  - Suspicious use of WriteProcessMemory
  PID:636
- - C:\Windows\SysWOW64\timeout.exe
    timeout 3
    3⤵
    - System Location Discovery: System Language Discovery
    - Delays execution with timeout.exe
    PID:1256
- - C:\Users\Admin\AppData\Roaming\GoogleUpdate.exe
    "C:\Users\Admin\AppData\Roaming\GoogleUpdate.exe"
    3⤵
    - Executes dropped EXE
    - System Location Discovery: System Language Discovery
    PID:1976

C:\Users\Admin\AppData\Roaming\GoogleUpdate.exe
"C:\Users\Admin\AppData\Roaming\GoogleUpdate.exe"
1⤵
- Executes dropped EXE
- System Location Discovery: System Language Discovery
- Suspicious use of AdjustPrivilegeToken
PID:4904

Network

MITRE ATT&CK Enterprise v16

Reconnaissance

Resource Development

Initial Access

Execution

Command and Scripting Interpreter

1

T1059

Windows Command Shell

1

T1059.003

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

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Downloads

tmp6A5D.tmp.bat

Path C:\Users\Admin\AppData\Local\Temp\tmp6A5D.tmp.bat
Size 156B
SHA256 5a5829a2abcbdfc2d605d6477e41026b79e06d84b3be8a9896a368cff64c1c4a
MD5 06e32899b41da363b6697d12dd9e7446
SHA1 6b42e643e498ba2fbf0226b096429ed26d8a4746
SHA512 61028a9a90bc413e36c981b5714fd48aa8d70f252b70962617b1bc7697b3caf163de4c023e63ff5b76d0f7ead64426d2324a518c1b5c654284919ef1ac025784
TLSH
T188C02B5365C9EA2F2805F81B17FFD5CD91B26C593F44BB90C304441D22C0888F4ED386
MD5 SHA1 SHA512 TLSH

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GoogleUpdate.exe

Path C:\Users\Admin\AppData\Roaming\GoogleUpdate.exe
Size 47KB
SHA256 41d7d8d9eef7819dff69c2fe448c4333b9eeeb0d0f4bf86489521abb0ce58d63
MD5 de7e82e617be73ced59585f3dd73b38d
SHA1 7c06d9c7490bed6fe3756c256bdf840ff9242241
SHA512 7bc47849631b32b0ce7efd88ab2a2fc2d3454d448ea38961a0f311c1529146125d7adb3e3418a342fb530d9aecb146c4d71160f16bed3182a03b6ea235c825c1
SSDEEP 768:QuANNTR4ydbWUnrGJmo2q7V/mxZ20tlNPIVJDw1y0bQ6zwuVvE+LPZgQraBDZAx:QuANNTRZ22Q/r0t0VJkNbQ6FVvECPuQf
TLSH
T1E7232C007BE98236F2BE4F74A9F22155867AB2673603D64D2CC441D75A13FC29A426FE
MD5 SHA1 SHA512 SSDEEP TLSH

Submit Download

memory/732-0-0x0000000000390000-0x00000000003A2000-memory.dmp

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memory/732-1-0x0000000004E10000-0x0000000004E20000-memory.dmp

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memory/732-2-0x0000000004D40000-0x0000000004DA6000-memory.dmp

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memory/732-3-0x0000000005200000-0x000000000529C000-memory.dmp

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Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v16

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