asyncrat | 6dbb801d621a57c4b4cb499acabaaa597c27db6050a7e98eb22d5111a0d4dea6

General

Target

rex.exe
Size

3.8MB
MD5

f9167c360e2d98e3d6cdc7bd1bbb6bbb
SHA1

5c1f2e1fb6c9767948ef64e822ef53b3059a8410
SHA256

6dbb801d621a57c4b4cb499acabaaa597c27db6050a7e98eb22d5111a0d4dea6
SHA512

d0e5eebe6a786321c3677d79ebbf0149d7fd5c4a0b95e717c8bd49c7f266a8bac9a077a473dd7a5711005afdb2bf9f1d95efed9fa7e2397b41a71b772c1883d6
SSDEEP

1536:Yu6ZdTv2S2deM1+paj/6GUIbJUuBoYudId44:Yu6vTv2S2dr1Aaj/1UIbJUuB4iu4

Score

10^/10

asyncrat default discovery rat

Malware Config

Extracted

Family

asyncrat

Version

0.5.8

Botnet

Default

C2

127.0.0.1:6606

127.0.0.1:7707

127.0.0.1:8808

Mutex

WJ7ad2hfOKxk

Attributes

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

aes.plain

Signatures

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

Async RAT payload 1 IoCs

rat

Processes:

resource	yara_rule
C:\Users\Admin\AppData\Local\Temp\svchost.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:

rex.exe

description ioc process

Key value queried \REGISTRY\USER\S-1-5-21-4089630652-1596403869-279772308-1000\Control Panel\International\Geo\Nation rex.exe
Executes dropped EXE 1 IoCs

Processes:

svchost.exe

pid process

2856 svchost.exe
Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s).

System Information Discovery
T1082

description	ioc	process
Key value queried	\REGISTRY\USER\S-1-5-21-4089630652-1596403869-279772308-1000\Control Panel\International\Geo\Nation	rex.exe

pid	process
2856	svchost.exe

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:

schtasks.exetimeout.exesvchost.exerex.execmd.execmd.exe

description	ioc	process
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	svchost.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	rex.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	cmd.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	cmd.exe

Delays execution with timeout.exe 1 IoCs
evasion

Processes:

timeout.exe

pid process

432 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

424 schtasks.exe

pid	process
432	timeout.exe

pid	process
424	schtasks.exe

Suspicious behavior: EnumeratesProcesses 21 IoCs

Processes:

rex.exe

pid	process
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe
1904	rex.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

Processes:

rex.exesvchost.exe

description pid process

Token: SeDebugPrivilege 1904 rex.exe
Token: SeDebugPrivilege 2856 svchost.exe

description	pid	process
Token: SeDebugPrivilege	1904	rex.exe
Token: SeDebugPrivilege	2856	svchost.exe

Suspicious use of WriteProcessMemory 15 IoCs

Processes:

rex.execmd.execmd.exe

description	pid	process	target process
PID 1904 wrote to memory of 3568	1904	rex.exe	cmd.exe
PID 1904 wrote to memory of 3568	1904	rex.exe	cmd.exe
PID 1904 wrote to memory of 3568	1904	rex.exe	cmd.exe
PID 1904 wrote to memory of 4496	1904	rex.exe	cmd.exe
PID 1904 wrote to memory of 4496	1904	rex.exe	cmd.exe
PID 1904 wrote to memory of 4496	1904	rex.exe	cmd.exe
PID 3568 wrote to memory of 424	3568	cmd.exe	schtasks.exe
PID 3568 wrote to memory of 424	3568	cmd.exe	schtasks.exe
PID 3568 wrote to memory of 424	3568	cmd.exe	schtasks.exe
PID 4496 wrote to memory of 432	4496	cmd.exe	timeout.exe
PID 4496 wrote to memory of 432	4496	cmd.exe	timeout.exe
PID 4496 wrote to memory of 432	4496	cmd.exe	timeout.exe
PID 4496 wrote to memory of 2856	4496	cmd.exe	svchost.exe
PID 4496 wrote to memory of 2856	4496	cmd.exe	svchost.exe
PID 4496 wrote to memory of 2856	4496	cmd.exe	svchost.exe

C:\Users\Admin\AppData\Local\Temp\rex.exe
"C:\Users\Admin\AppData\Local\Temp\rex.exe"
1⤵
- Checks computer location settings
- System Location Discovery: System Language Discovery
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:1904

C:\Windows\SysWOW64\cmd.exe
"C:\Windows\System32\cmd.exe" /c schtasks /create /f /sc onlogon /rl highest /tn "svchost" /tr '"C:\Users\Admin\AppData\Local\Temp\svchost.exe"' & exit
2⤵
- System Location Discovery: System Language Discovery
- Suspicious use of WriteProcessMemory
PID:3568

C:\Windows\SysWOW64\schtasks.exe
schtasks /create /f /sc onlogon /rl highest /tn "svchost" /tr '"C:\Users\Admin\AppData\Local\Temp\svchost.exe"'
3⤵
- System Location Discovery: System Language Discovery
- Scheduled Task/Job: Scheduled Task
PID:424

C:\Windows\SysWOW64\cmd.exe
C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\tmpD5DE.tmp.bat""
2⤵
- System Location Discovery: System Language Discovery
- Suspicious use of WriteProcessMemory
PID:4496

C:\Windows\SysWOW64\timeout.exe
timeout 3
3⤵
- System Location Discovery: System Language Discovery
- Delays execution with timeout.exe
PID:432

C:\Users\Admin\AppData\Local\Temp\svchost.exe
"C:\Users\Admin\AppData\Local\Temp\svchost.exe"
3⤵
- Executes dropped EXE
- System Location Discovery: System Language Discovery
- Suspicious use of AdjustPrivilegeToken
PID:2856

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

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Downloads

C:\Users\Admin\AppData\Local\Temp\svchost.exe

Filesize
3.8MB

MD5
f9167c360e2d98e3d6cdc7bd1bbb6bbb

SHA1
5c1f2e1fb6c9767948ef64e822ef53b3059a8410

SHA256
6dbb801d621a57c4b4cb499acabaaa597c27db6050a7e98eb22d5111a0d4dea6

SHA512
d0e5eebe6a786321c3677d79ebbf0149d7fd5c4a0b95e717c8bd49c7f266a8bac9a077a473dd7a5711005afdb2bf9f1d95efed9fa7e2397b41a71b772c1883d6

Download Submit
C:\Users\Admin\AppData\Local\Temp\tmpD5DE.tmp.bat

Filesize
154B

MD5
8c86b4d625a619888f049d8998170695

SHA1
bbd9cc32208aab63f77acfcd838d0a6d604d18a0

SHA256
4ab3b09d6dcce9514deceea00aa909fdbbd5b958c14ff7d48c60f805b9e6e6c5

SHA512
1a2ef3994d3ccd416252f35e57d306a5dd315df6e981268cff8b120f7a8dce29a5c0e4bf77aeef95985a1c91a9fc65968cc3ecfb3c32a50666a08d4b015f661c

Download Submit
memory/1904-0-0x000000007457E000-0x000000007457F000-memory.dmp

Filesize
4KB

Download
memory/1904-1-0x0000000000E60000-0x0000000000E72000-memory.dmp

Filesize
72KB

Download
memory/1904-2-0x0000000074570000-0x0000000074D20000-memory.dmp

Filesize
7.7MB

Download
memory/1904-3-0x00000000032B0000-0x0000000003316000-memory.dmp

Filesize
408KB

Download
memory/1904-4-0x0000000005BE0000-0x0000000005C7C000-memory.dmp

Filesize
624KB

Download
memory/1904-9-0x0000000074570000-0x0000000074D20000-memory.dmp

Filesize
7.7MB

Download
memory/2856-14-0x00000000744D0000-0x0000000074C80000-memory.dmp

Filesize
7.7MB

Download
memory/2856-15-0x00000000744D0000-0x0000000074C80000-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