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

resource	yara_rule
behavioral2/files/0x0007000000023c97-11.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-1-5-21-1045960512-3948844814-3059691613-1000\Control Panel\International\Geo\Nation	AsyncClient.exe

Executes dropped EXE 1 IoCs

pid	Process
1592	Sync.exe

Legitimate hosting services abused for malware hosting/C2 1 TTPs 2 IoCs

Web Service

T1102

flow	ioc
16	pastebin.com
17	pastebin.com

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	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	schtasks.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	timeout.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	Sync.exe

Delays execution with timeout.exe 1 IoCs

evasion

pid	Process
1340	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
2588	schtasks.exe

Suspicious behavior: EnumeratesProcesses 23 IoCs

pid	Process
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe
4192	AsyncClient.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	4192	AsyncClient.exe
Token: SeDebugPrivilege	1592	Sync.exe

Suspicious use of WriteProcessMemory 15 IoCs

description	pid	Process	procid_target
PID 4192 wrote to memory of 5060	4192	AsyncClient.exe	88
PID 4192 wrote to memory of 5060	4192	AsyncClient.exe	88
PID 4192 wrote to memory of 5060	4192	AsyncClient.exe	88
PID 4192 wrote to memory of 672	4192	AsyncClient.exe	90
PID 4192 wrote to memory of 672	4192	AsyncClient.exe	90
PID 4192 wrote to memory of 672	4192	AsyncClient.exe	90
PID 5060 wrote to memory of 2588	5060	cmd.exe	92
PID 5060 wrote to memory of 2588	5060	cmd.exe	92
PID 5060 wrote to memory of 2588	5060	cmd.exe	92
PID 672 wrote to memory of 1340	672	cmd.exe	93
PID 672 wrote to memory of 1340	672	cmd.exe	93
PID 672 wrote to memory of 1340	672	cmd.exe	93
PID 672 wrote to memory of 1592	672	cmd.exe	96
PID 672 wrote to memory of 1592	672	cmd.exe	96
PID 672 wrote to memory of 1592	672	cmd.exe	96

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:4192
- 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:5060
- - 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:2588
- C:\Windows\SysWOW64\cmd.exe
  C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\tmpBA28.tmp.bat""
  2⤵
  - System Location Discovery: System Language Discovery
  - Suspicious use of WriteProcessMemory
  PID:672
- - C:\Windows\SysWOW64\timeout.exe
    timeout 3
    3⤵
    - System Location Discovery: System Language Discovery
    - Delays execution with timeout.exe
    PID:1340
- - 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:1592

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\tmpBA28.tmp.bat

Filesize
148B

MD5
fbdf5f4cef856023bf7f334d770df363

SHA1
4d6adbb957e7a1c979430703f95c3647d4f956d8

SHA256
a433e9f12592fd68aa68a7dfdf838cb4cbf3e85286ddbf66b89d1f5d79687c7f

SHA512
22d422f20a416ca57be066e89a95059da5a89b4b7169a0291a9229e82606fc592790f5466bbfc060ddd7841f0a0a2fbd572a48d5c149979f2b5b6f07a0d2981b

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

Filesize
47KB

MD5
678c7b99496c1e045a6f8a7072f41902

SHA1
fbc4bf034a1d4b0b7f0777da3dbf63ba2ea7d5de

SHA256
b89c64e6cb8ac56910849b3340322f3ed1aa77be3aee2a9e081ff08819ce43bd

SHA512
ac152cb621f2503178f82dfca62816cb13c91551c3f0c181c245117b3a1e2d9dbe022dce109f8e192d74e31c251a857770974f03c5f2b528017fe66e79195fc6

Download Submit
memory/1592-13-0x0000000074650000-0x0000000074E00000-memory.dmp

Filesize
7.7MB

Download
memory/1592-14-0x0000000074650000-0x0000000074E00000-memory.dmp

Filesize
7.7MB

Download
memory/4192-0-0x00000000746FE000-0x00000000746FF000-memory.dmp

Filesize
4KB

Download
memory/4192-1-0x00000000000D0000-0x00000000000E2000-memory.dmp

Filesize
72KB

Download
memory/4192-2-0x00000000746F0000-0x0000000074EA0000-memory.dmp

Filesize
7.7MB

Download
memory/4192-3-0x0000000004AB0000-0x0000000004B4C000-memory.dmp

Filesize
624KB

Download
memory/4192-8-0x00000000746F0000-0x0000000074EA0000-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