asyncrat | b89c64e6cb8ac56910849b3340322f3ed1aa77be3aee2a9e081ff08819ce43bd

General

Target

AsyncClient.exe
Size

47KB
MD5

678c7b99496c1e045a6f8a7072f41902
SHA1

fbc4bf034a1d4b0b7f0777da3dbf63ba2ea7d5de
SHA256

b89c64e6cb8ac56910849b3340322f3ed1aa77be3aee2a9e081ff08819ce43bd
SHA512

ac152cb621f2503178f82dfca62816cb13c91551c3f0c181c245117b3a1e2d9dbe022dce109f8e192d74e31c251a857770974f03c5f2b528017fe66e79195fc6
SSDEEP

768:QuYH9T3kH1jWUvTqRmo2qbcrFgnNyGzYk5PIqPESVOs0bXbva5XPfG1tRulaADVg:QuYH9T34y2nFg7X2qPJEbDatPfG1tRue

Score

10^/10

asyncrat default discovery rat

Malware Config

Extracted

Family

asyncrat

Version

0.5.8

Botnet

Default

Mutex

juGfnQMxS4Ze

Attributes

delay
3
install
true
install_file
Sync.exe
install_folder
%AppData%
pastebin_config
https://pastebin.com/raw/s14cUU5G

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

Processes:

resource	yara_rule
C:\Users\Admin\AppData\Roaming\Sync.exe	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

Processes:

AsyncClient.exe

description	ioc	process
Key value queried	\REGISTRY\USER\S-1-5-21-3227495264-2217614367-4027411560-1000\Control Panel\International\Geo\Nation	AsyncClient.exe

Executes dropped EXE 1 IoCs

Processes:

Sync.exe

pid process

512 Sync.exe
Legitimate hosting services abused for malware hosting/C2 1 TTPs 2 IoCs

Web Service
T1102

Processes:

flow ioc

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

System Information Discovery
T1082

pid	process
512	Sync.exe

flow	ioc
25	pastebin.com
26	pastebin.com

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

Processes:

AsyncClient.execmd.execmd.exetimeout.exeschtasks.exeSync.exe

description	ioc	process
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	AsyncClient.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
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	Sync.exe

Delays execution with timeout.exe 1 IoCs
evasion

Processes:

timeout.exe

pid process

1964 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

Processes:

schtasks.exe

pid process

4128 schtasks.exe

pid	process
1964	timeout.exe

pid	process
4128	schtasks.exe

Suspicious behavior: EnumeratesProcesses 23 IoCs

Processes:

AsyncClient.exe

pid	process
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe
1908	AsyncClient.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

Processes:

AsyncClient.exeSync.exe

description pid process

Token: SeDebugPrivilege 1908 AsyncClient.exe
Token: SeDebugPrivilege 512 Sync.exe

description	pid	process
Token: SeDebugPrivilege	1908	AsyncClient.exe
Token: SeDebugPrivilege	512	Sync.exe

Suspicious use of WriteProcessMemory 15 IoCs

Processes:

AsyncClient.execmd.execmd.exe

description	pid	process	target process
PID 1908 wrote to memory of 4884	1908	AsyncClient.exe	cmd.exe
PID 1908 wrote to memory of 4884	1908	AsyncClient.exe	cmd.exe
PID 1908 wrote to memory of 4884	1908	AsyncClient.exe	cmd.exe
PID 1908 wrote to memory of 3148	1908	AsyncClient.exe	cmd.exe
PID 1908 wrote to memory of 3148	1908	AsyncClient.exe	cmd.exe
PID 1908 wrote to memory of 3148	1908	AsyncClient.exe	cmd.exe
PID 3148 wrote to memory of 1964	3148	cmd.exe	timeout.exe
PID 3148 wrote to memory of 1964	3148	cmd.exe	timeout.exe
PID 3148 wrote to memory of 1964	3148	cmd.exe	timeout.exe
PID 4884 wrote to memory of 4128	4884	cmd.exe	schtasks.exe
PID 4884 wrote to memory of 4128	4884	cmd.exe	schtasks.exe
PID 4884 wrote to memory of 4128	4884	cmd.exe	schtasks.exe
PID 3148 wrote to memory of 512	3148	cmd.exe	Sync.exe
PID 3148 wrote to memory of 512	3148	cmd.exe	Sync.exe
PID 3148 wrote to memory of 512	3148	cmd.exe	Sync.exe

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:1908
- C:\Windows\SysWOW64\cmd.exe
  "C:\Windows\System32\cmd.exe" /c schtasks /create /f /sc onlogon /rl highest /tn "Sync" /tr '"C:\Users\Admin\AppData\Roaming\Sync.exe"' & exit
  2⤵
  - System Location Discovery: System Language Discovery
  - Suspicious use of WriteProcessMemory
  PID:4884
- - C:\Windows\SysWOW64\schtasks.exe
    schtasks /create /f /sc onlogon /rl highest /tn "Sync" /tr '"C:\Users\Admin\AppData\Roaming\Sync.exe"'
    3⤵
    - System Location Discovery: System Language Discovery
    - Scheduled Task/Job: Scheduled Task
    PID:4128
- C:\Windows\SysWOW64\cmd.exe
  C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\tmp9AE8.tmp.bat""
  2⤵
  - System Location Discovery: System Language Discovery
  - Suspicious use of WriteProcessMemory
  PID:3148
- - C:\Windows\SysWOW64\timeout.exe
    timeout 3
    3⤵
    - System Location Discovery: System Language Discovery
    - Delays execution with timeout.exe
    PID:1964
- - C:\Users\Admin\AppData\Roaming\Sync.exe
    "C:\Users\Admin\AppData\Roaming\Sync.exe"
    3⤵
    - Executes dropped EXE
    - System Location Discovery: System Language Discovery
    - Suspicious use of AdjustPrivilegeToken
    PID:512

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

Web Service

1

T1102

Exfiltration

Impact

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Downloads

C:\Users\Admin\AppData\Local\Temp\tmp9AE8.tmp.bat

Filesize
148B

MD5
cfe1356f39c7819887a435b65b2cc1b4

SHA1
b0d31d5d0a347f9570b3709f47adbd73b5a8ef0a

SHA256
3660092d9f3d15af343dd361b1443166fbd0bda482ff1c4f732e40bc0d1b706b

SHA512
ddc1b8785353a009fe186627eb0473e270b9cd24fa240d9af065935466a6b6592f2987a465f6293985079f4ba5019e0154ea5afed83370e84e960496c93fd862

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

Filesize
47KB

MD5
678c7b99496c1e045a6f8a7072f41902

SHA1
fbc4bf034a1d4b0b7f0777da3dbf63ba2ea7d5de

SHA256
b89c64e6cb8ac56910849b3340322f3ed1aa77be3aee2a9e081ff08819ce43bd

SHA512
ac152cb621f2503178f82dfca62816cb13c91551c3f0c181c245117b3a1e2d9dbe022dce109f8e192d74e31c251a857770974f03c5f2b528017fe66e79195fc6

Download Submit
memory/512-13-0x0000000074AF0000-0x00000000752A0000-memory.dmp

Filesize
7.7MB

Download
memory/512-14-0x0000000074AF0000-0x00000000752A0000-memory.dmp

Filesize
7.7MB

Download
memory/1908-0-0x0000000074B7E000-0x0000000074B7F000-memory.dmp

Filesize
4KB

Download
memory/1908-1-0x0000000000DB0000-0x0000000000DC2000-memory.dmp

Filesize
72KB

Download
memory/1908-2-0x0000000074B70000-0x0000000075320000-memory.dmp

Filesize
7.7MB

Download
memory/1908-3-0x0000000005800000-0x000000000589C000-memory.dmp

Filesize
624KB

Download
memory/1908-9-0x0000000074B70000-0x0000000075320000-memory.dmp

Filesize
7.7MB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads