asyncrat | 3e4cb0728d9fa9cfa6c78456e8a6d10413fe4f63a771c4b188d629ef7a1601e9

General

Target
tmpwxc4cter.exe
Size 45KB
Sample260602-kgnflagz8x
SHA256 3e4cb0728d9fa9cfa6c78456e8a6d10413fe4f63a771c4b188d629ef7a1601e9
MD5 693ab39bba0a3185183c83910d990b54
SHA1 eaad194e25a063f68a3b8590977201c91c3a5c45
SHA512 f7778479abf16dbefc59b93b5871b4085d11dc4181d00377d10cf7d45b4854ed04877079a52d61b94367641f3ce09953ade2279bdfc18d88d84b1261d3ce915d
SSDEEP 768:Bupk9Tx5PWZZWUvfyRmo2qg/fPLzizpvtLjZPI9zjbugXNin1bIdKoBDZjx:Bupk9TxtOO2bfHi1VjW93bRX8nadKOdd
TLSH
T124233C003BE8812BF2BE5F7899F26245867AF2632603D54A1CC451DB5723FC696436FE
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

viet69.net:443
viet69.net:80
viet69.net:7797
viet69.net:8707
viet69.net:6620
www.viet69.net:443
www.viet69.net:80
www.viet69.net:7797
www.viet69.net:8707
www.viet69.net:6620
cl0p.viet69.net:443
cl0p.viet69.net:80
cl0p.viet69.net:7797
cl0p.viet69.net:8707
cl0p.viet69.net:6620
klez.viet69.net:443
klez.viet69.net:80
klez.viet69.net:7797
klez.viet69.net:8707
klez.viet69.net:6620
nanocore.viet69.net:443
nanocore.viet69.net:80
nanocore.viet69.net:7797
nanocore.viet69.net:8707
nanocore.viet69.net:6620

Mutex

kKFO1LqgWPaG

Attributes

delay
0
install
true
install_file
5yyo.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 2 IoCs

rat

resource	yara_rule
behavioral2/files/0x000a00000002436a-8.dat	family_asyncrat
behavioral2/memory/2876-10-0x0000000005520000-0x0000000005530000-memory.dmp	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-1-5-21-2937465464-4167303362-2236413517-1000\Control Panel\International\Geo\Nation	tmpwxc4cter.exe

Executes dropped EXE 2 IoCs

pid	Process
2876	5yyo.exe
116	5yyo.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 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	5yyo.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	5yyo.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	tmpwxc4cter.exe
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	timeout.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	schtasks.exe

Delays execution with timeout.exe 1 IoCs

defense_evasion

pid	Process
4588	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
3376	schtasks.exe

Suspicious behavior: EnumeratesProcesses 21 IoCs

pid	Process
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe
3372	tmpwxc4cter.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	3372	tmpwxc4cter.exe
Token: SeDebugPrivilege	2876	5yyo.exe

Suspicious use of WriteProcessMemory 5 IoCs

description	pid	Process	procid_target
PID 3372 wrote to memory of 4736	3372	tmpwxc4cter.exe	89
PID 3372 wrote to memory of 1456	3372	tmpwxc4cter.exe	91
PID 1456 wrote to memory of 4588	1456	cmd.exe	93
PID 4736 wrote to memory of 3376	4736	cmd.exe	94
PID 1456 wrote to memory of 116	1456	cmd.exe	98

C:\Users\Admin\AppData\Local\Temp\tmpwxc4cter.exe
"C:\Users\Admin\AppData\Local\Temp\tmpwxc4cter.exe"
1⤵
- Checks computer location settings
- System Location Discovery: System Language Discovery
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:3372
- C:\Windows\SysWOW64\cmd.exe
  "C:\Windows\System32\cmd.exe" /c schtasks /create /f /sc onlogon /rl highest /tn "5yyo" /tr '"C:\Users\Admin\AppData\Roaming\5yyo.exe"' & exit
  2⤵
  - System Location Discovery: System Language Discovery
  - Suspicious use of WriteProcessMemory
  PID:4736
- - C:\Windows\SysWOW64\schtasks.exe
    schtasks /create /f /sc onlogon /rl highest /tn "5yyo" /tr '"C:\Users\Admin\AppData\Roaming\5yyo.exe"'
    3⤵
    - System Location Discovery: System Language Discovery
    - Scheduled Task/Job: Scheduled Task
    PID:3376
- C:\Windows\SysWOW64\cmd.exe
  C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\tmp948A.tmp.bat""
  2⤵
  - System Location Discovery: System Language Discovery
  - Suspicious use of WriteProcessMemory
  PID:1456
- - C:\Windows\SysWOW64\timeout.exe
    timeout 3
    3⤵
    - System Location Discovery: System Language Discovery
    - Delays execution with timeout.exe
    PID:4588
- - C:\Users\Admin\AppData\Roaming\5yyo.exe
    "C:\Users\Admin\AppData\Roaming\5yyo.exe"
    3⤵
    - Executes dropped EXE
    - System Location Discovery: System Language Discovery
    PID:116

C:\Users\Admin\AppData\Roaming\5yyo.exe
"C:\Users\Admin\AppData\Roaming\5yyo.exe"
1⤵
- Executes dropped EXE
- System Location Discovery: System Language Discovery
- Suspicious use of AdjustPrivilegeToken
PID:2876

Network

MITRE ATT&CK Enterprise v16

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

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Downloads

tmp948A.tmp.bat

Path C:\Users\Admin\AppData\Local\Temp\tmp948A.tmp.bat
Size 148B
SHA256 eca387e1f002dab7dfb0d2d284f2c2b94e943752bd67139769723fff52b6173c
MD5 96b6d2404afd428a075f3fda28ec3fa1
SHA1 b4b8dac127591ace61d71857b1951e3705c2fce3
SHA512 bdbdc7199154375ad53b6c100d8d913aa42b8dc272911b655bec2bd7bc4368418e01003c3b16adf0580ad062a2fd7a8f47215eef4391bdf512c2c93432a425ff
TLSH
T1C7C02B5261C6EA0E3C09242302FED49E9172BC1D3F40FB40CB04448D3280C48F0DD342
MD5 SHA1 SHA512 TLSH

Submit Download

5yyo.exe

Path C:\Users\Admin\AppData\Roaming\5yyo.exe
Size 45KB
SHA256 3e4cb0728d9fa9cfa6c78456e8a6d10413fe4f63a771c4b188d629ef7a1601e9
MD5 693ab39bba0a3185183c83910d990b54
SHA1 eaad194e25a063f68a3b8590977201c91c3a5c45
SHA512 f7778479abf16dbefc59b93b5871b4085d11dc4181d00377d10cf7d45b4854ed04877079a52d61b94367641f3ce09953ade2279bdfc18d88d84b1261d3ce915d
SSDEEP 768:Bupk9Tx5PWZZWUvfyRmo2qg/fPLzizpvtLjZPI9zjbugXNin1bIdKoBDZjx:Bupk9TxtOO2bfHi1VjW93bRX8nadKOdd
TLSH
T124233C003BE8812BF2BE5F7899F26245867AF2632603D54A1CC451DB5723FC696436FE
MD5 SHA1 SHA512 SSDEEP TLSH

Submit Download

memory/2876-10-0x0000000005520000-0x0000000005530000-memory.dmp

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memory/2876-13-0x0000000005520000-0x0000000005530000-memory.dmp

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memory/3372-0-0x0000000000B70000-0x0000000000B82000-memory.dmp

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memory/3372-1-0x00000000054F0000-0x0000000005500000-memory.dmp

Download

memory/3372-2-0x00000000055A0000-0x000000000563C000-memory.dmp

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Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v16

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