avoslocker | be19681b21f2a573b477444a788e00eb8dad2d740d11c02f14e878fe5b89fa70

General

Target

075cb88f83fbe4ad2ae0f553697e7bdf.exe
Size

921KB
MD5

075cb88f83fbe4ad2ae0f553697e7bdf
SHA1

773dce7c01a42e8371cf49ceda07f26cba0907b9
SHA256

be19681b21f2a573b477444a788e00eb8dad2d740d11c02f14e878fe5b89fa70
SHA512

3f0a503acbfffc79eed37597d59e313c31f6b5451fdad79eacd611119ec17a4a245928079993689811a5695ad310951a282b1c493d08bdb31aa2b5fdbf63bf67
SSDEEP

24576:SnkXEg1ZlhKG+WWZtCpDCE5Ie534SCeTpOl135HlIp:SkXEg1ZlIzZtCpGE5j5oSHOlxdlIp

Score

10^/10

avoslocker ransomware

Malware Config

Signatures

Avoslocker Ransomware
Avoslocker is a relatively new ransomware, that was observed in late June and early July, 2021.
ransomware avoslocker
Renames multiple (144) files with added filename extension
This suggests ransomware activity of encrypting all the files on the system.
ransomware

Sets desktop wallpaper using registry 2 TTPs 1 IoCs

ransomware

Defacement

T1491

Modify Registry

T1112

Processes:

reg.exe

description	ioc	process
Set value (str)	\REGISTRY\USER\S-1-5-21-996941297-2279405024-2328152752-1000\Control Panel\Desktop\Wallpaper = "C:\\Users\\Admin\\AppData\\Local\\Temp\\681291657.png"	reg.exe

Suspicious behavior: EnumeratesProcesses 2 IoCs

Processes:

powershell.exe

pid process

5308 powershell.exe
5308 powershell.exe
Suspicious use of AdjustPrivilegeToken 1 IoCs

Processes:

powershell.exe

description pid process

Token: SeDebugPrivilege 5308 powershell.exe

pid	process
5308	powershell.exe
5308	powershell.exe

description	pid	process
Token: SeDebugPrivilege	5308	powershell.exe

Suspicious use of WriteProcessMemory 9 IoCs

Processes:

075cb88f83fbe4ad2ae0f553697e7bdf.exepowershell.exe

description	pid	process	target process
PID 1092 wrote to memory of 5308	1092	075cb88f83fbe4ad2ae0f553697e7bdf.exe	powershell.exe
PID 1092 wrote to memory of 5308	1092	075cb88f83fbe4ad2ae0f553697e7bdf.exe	powershell.exe
PID 1092 wrote to memory of 5308	1092	075cb88f83fbe4ad2ae0f553697e7bdf.exe	powershell.exe
PID 5308 wrote to memory of 4912	5308	powershell.exe	reg.exe
PID 5308 wrote to memory of 4912	5308	powershell.exe	reg.exe
PID 5308 wrote to memory of 4912	5308	powershell.exe	reg.exe
PID 5308 wrote to memory of 4932	5308	powershell.exe	rundll32.exe
PID 5308 wrote to memory of 4932	5308	powershell.exe	rundll32.exe
PID 5308 wrote to memory of 4932	5308	powershell.exe	rundll32.exe

C:\Users\Admin\AppData\Local\Temp\075cb88f83fbe4ad2ae0f553697e7bdf.exe
"C:\Users\Admin\AppData\Local\Temp\075cb88f83fbe4ad2ae0f553697e7bdf.exe"
1⤵
- Suspicious use of WriteProcessMemory
PID:1092
- C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe
  powershell -Command "$a = [System.IO.File]::ReadAllText(\"C:\GET_YOUR_FILES_BACK.txt\");Add-Type -AssemblyName System.Drawing;$filename = \"$env:temp\$(Get-Random).png\";$bmp = new-object System.Drawing.Bitmap 1920,1080;$font = new-object System.Drawing.Font Consolas,10;$brushBg = [System.Drawing.Brushes]::Black;$brushFg = [System.Drawing.Brushes]::White;$format = [System.Drawing.StringFormat]::GenericDefault;$format.Alignment = [System.Drawing.StringAlignment]::Center;$format.LineAlignment = [System.Drawing.StringAlignment]::Center;$graphics = [System.Drawing.Graphics]::FromImage($bmp);$graphics.FillRectangle($brushBg,0,0,$bmp.Width,$bmp.Height);$graphics.DrawString($a,$font,$brushFg,[System.Drawing.RectangleF]::FromLTRB(0, 0, 1920, 1080),$format);$graphics.Dispose();$bmp.Save($filename);reg add \"HKEY_CURRENT_USER\Control Panel\Desktop\" /v Wallpaper /t REG_SZ /d $filename /f;Start-Sleep 1;rundll32.exe user32.dll, UpdatePerUserSystemParameters, 0, $false;"
  2⤵
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of AdjustPrivilegeToken
  - Suspicious use of WriteProcessMemory
  PID:5308
- - C:\Windows\SysWOW64\reg.exe
    "C:\Windows\system32\reg.exe" add "HKEY_CURRENT_USER\Control Panel\Desktop" /v Wallpaper /t REG_SZ /d C:\Users\Admin\AppData\Local\Temp\681291657.png /f
    3⤵
    - Sets desktop wallpaper using registry
    PID:4912
- - C:\Windows\SysWOW64\rundll32.exe
    "C:\Windows\system32\rundll32.exe" user32.dll UpdatePerUserSystemParameters 0 False
    3⤵
    PID:4932

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Persistence

Privilege Escalation

Defense Evasion

Modify Registry

1

T1112

Credential Access

Discovery

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Defacement

1

T1491

Replay Monitor

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Downloads

C:\GET_YOUR_FILES_BACK.txt

Filesize
1011B

MD5
d90d05a5fea9c28b3bf2b55f808c3a45

SHA1
7774c79c85b4401acfc56002f9e8a3e10e8a7b60

SHA256
8a9b224d68a718e7cd4da069a158408d9c71fb8ecc4e4a6581982d7a35b29cec

SHA512
783d830a0d75911da6878ea58f7191f1438a429e232c63db86e6f09a1bb390ec7ee72f10db1ee695177686cacab24c9e58f61e7d403d75dd9c817c592131170a

Download Submit
C:\Users\Admin\AppData\Local\Temp\__PSScriptPolicyTest_c1glbve5.nz5.ps1

Filesize
60B

MD5
d17fe0a3f47be24a6453e9ef58c94641

SHA1
6ab83620379fc69f80c0242105ddffd7d98d5d9d

SHA256
96ad1146eb96877eab5942ae0736b82d8b5e2039a80d3d6932665c1a4c87dcf7

SHA512
5b592e58f26c264604f98f6aa12860758ce606d1c63220736cf0c779e4e18e3cec8706930a16c38b20161754d1017d1657d35258e58ca22b18f5b232880dec82

Download Submit
memory/5308-410-0x0000000005530000-0x0000000005B58000-memory.dmp

Filesize
6.2MB

Download
memory/5308-423-0x0000000005F60000-0x00000000062B4000-memory.dmp

Filesize
3.3MB

Download
memory/5308-408-0x0000000002A30000-0x0000000002A40000-memory.dmp

Filesize
64KB

Download
memory/5308-411-0x0000000005BB0000-0x0000000005BD2000-memory.dmp

Filesize
136KB

Download
memory/5308-412-0x0000000005CD0000-0x0000000005D36000-memory.dmp

Filesize
408KB

Download
memory/5308-413-0x0000000005DF0000-0x0000000005E56000-memory.dmp

Filesize
408KB

Download
memory/5308-407-0x0000000074730000-0x0000000074EE0000-memory.dmp

Filesize
7.7MB

Download
memory/5308-409-0x0000000002E60000-0x0000000002E96000-memory.dmp

Filesize
216KB

Download
memory/5308-424-0x0000000006450000-0x000000000646E000-memory.dmp

Filesize
120KB

Download
memory/5308-425-0x0000000006490000-0x00000000064DC000-memory.dmp

Filesize
304KB

Download
memory/5308-427-0x0000000002A30000-0x0000000002A40000-memory.dmp

Filesize
64KB

Download
memory/5308-429-0x00000000069A0000-0x00000000069BA000-memory.dmp

Filesize
104KB

Download
memory/5308-428-0x0000000007C50000-0x00000000082CA000-memory.dmp

Filesize
6.5MB

Download
memory/5308-430-0x0000000007820000-0x00000000078B2000-memory.dmp

Filesize
584KB

Download
memory/5308-434-0x0000000074730000-0x0000000074EE0000-memory.dmp

Filesize
7.7MB

Download

Analysis

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