mountlocker | 6f9bed90c1d6df1c7b259f832130b5fef5e0d0c9dc6c2564dad53dc0ca30bb0e

General

Target

6f9bed90c1d6df1c7b259f832130b5fef5e0d0c9dc6c2564dad53dc0ca30bb0e_unpacked.dll
Size

68KB
MD5

49d8bd6dcaa501ca742bd686c161e5e0
SHA1

9acdd840615e4f4cd37f50e66b7bb7bb222d4fca
SHA256

6f9bed90c1d6df1c7b259f832130b5fef5e0d0c9dc6c2564dad53dc0ca30bb0e
SHA512

26d480f4480c99093859d3bb697dacc69c7165fc75603c717db6c1d0959463d7d9a33a32d3e1ec5360b0d031db4b77734f0ebcbf2bafb46b7390e1967d8a7b12
SSDEEP

768:PjzkUtPX7y4J6IjDcGopwx2P+9n+PLcHosFBLtuBDUaDO2y:0aXG4HtEPina7AdY3y

Score

10^/10

mountlocker ransomware

Malware Config

Signatures

MountLocker Ransomware
Ransomware family first seen in late 2020, which threatens to leak files if ransom is not paid.
ransomware mountlocker

Modifies extensions of user files 10 IoCs

Ransomware generally changes the extension on encrypted files.

ransomware

Processes:

rundll32.exe

description	ioc	process
File renamed	C:\Users\Admin\Pictures\WriteUnprotect.raw => \??\c:\Users\Admin\Pictures\WriteUnprotect.raw.ReadManual.72707D3B	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Pictures\DisconnectSend.tiff	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Pictures\HideConfirm.tiff	rundll32.exe
File renamed	C:\Users\Admin\Pictures\PopExpand.png => \??\c:\Users\Admin\Pictures\PopExpand.png.ReadManual.72707D3B	rundll32.exe
File renamed	C:\Users\Admin\Pictures\StepBackup.tif => \??\c:\Users\Admin\Pictures\StepBackup.tif.ReadManual.72707D3B	rundll32.exe
File renamed	C:\Users\Admin\Pictures\UnblockHide.tif => \??\c:\Users\Admin\Pictures\UnblockHide.tif.ReadManual.72707D3B	rundll32.exe
File renamed	C:\Users\Admin\Pictures\ApprovePush.tif => \??\c:\Users\Admin\Pictures\ApprovePush.tif.ReadManual.72707D3B	rundll32.exe
File renamed	C:\Users\Admin\Pictures\DisconnectSend.tiff => \??\c:\Users\Admin\Pictures\DisconnectSend.tiff.ReadManual.72707D3B	rundll32.exe
File renamed	C:\Users\Admin\Pictures\HideConfirm.tiff => \??\c:\Users\Admin\Pictures\HideConfirm.tiff.ReadManual.72707D3B	rundll32.exe
File renamed	C:\Users\Admin\Pictures\UsePop.tif => \??\c:\Users\Admin\Pictures\UsePop.tif.ReadManual.72707D3B	rundll32.exe

Drops desktop.ini file(s) 25 IoCs

Processes:

rundll32.exe

description	ioc	process
File opened for modification	\??\c:\Users\Public\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Public\Music\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\3D Objects\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Contacts\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Documents\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Favorites\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Music\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Public\AccountPictures\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Public\Libraries\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Public\Videos\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Desktop\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Favorites\Links\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Links\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Pictures\Saved Pictures\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Saved Games\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Public\Documents\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Public\Pictures\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\OneDrive\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Pictures\Camera Roll\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Pictures\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Videos\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Public\Desktop\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Public\Downloads\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Downloads\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Searches\desktop.ini	rundll32.exe

Drops file in Program Files directory 2 IoCs

Processes:

rundll32.exe

description	ioc	process
File created	\??\c:\Program Files\RecoveryManual.html	rundll32.exe
File created	\??\c:\Program Files (x86)\RecoveryManual.html	rundll32.exe

Modifies registry class 5 IoCs

Processes:

rundll32.exe

description	ioc	process
Key created	\REGISTRY\USER\S-1-5-21-4238149048-355649189-894321705-1000_Classes\.72707D3B\shell\Open\command	rundll32.exe
Key created	\REGISTRY\USER\S-1-5-21-4238149048-355649189-894321705-1000_Classes\.72707D3B	rundll32.exe
Key created	\REGISTRY\USER\S-1-5-21-4238149048-355649189-894321705-1000_Classes\.72707D3B\shell	rundll32.exe
Key created	\REGISTRY\USER\S-1-5-21-4238149048-355649189-894321705-1000_Classes\.72707D3B\shell\Open	rundll32.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-4238149048-355649189-894321705-1000_Classes\.72707D3B\shell\Open\command\ = "explorer.exe RecoveryManual.html"	rundll32.exe

Suspicious behavior: EnumeratesProcesses 2 IoCs

Processes:

rundll32.exe

pid process

468 rundll32.exe
468 rundll32.exe
Suspicious use of AdjustPrivilegeToken 2 IoCs

Processes:

rundll32.exe

description pid process

Token: SeRestorePrivilege 468 rundll32.exe
Token: SeDebugPrivilege 468 rundll32.exe

pid	process
468	rundll32.exe
468	rundll32.exe

description	pid	process
Token: SeRestorePrivilege	468	rundll32.exe
Token: SeDebugPrivilege	468	rundll32.exe

Suspicious use of WriteProcessMemory 4 IoCs

Processes:

rundll32.execmd.exe

description	pid	process	target process
PID 468 wrote to memory of 1484	468	rundll32.exe	cmd.exe
PID 468 wrote to memory of 1484	468	rundll32.exe	cmd.exe
PID 1484 wrote to memory of 4680	1484	cmd.exe	attrib.exe
PID 1484 wrote to memory of 4680	1484	cmd.exe	attrib.exe

Views/modifies file attributes 1 TTPs 1 IoCs
evasion

Hidden Files and Directories
T1158

Processes:

attrib.exe

pid process

4680 attrib.exe

pid	process
4680	attrib.exe

C:\Windows\system32\rundll32.exe
rundll32.exe C:\Users\Admin\AppData\Local\Temp\6f9bed90c1d6df1c7b259f832130b5fef5e0d0c9dc6c2564dad53dc0ca30bb0e_unpacked.dll,#1
1⤵
- Modifies extensions of user files
- Drops desktop.ini file(s)
- Drops file in Program Files directory
- Modifies registry class
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:468
- C:\Windows\system32\cmd.exe
  C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\\0E572CAD.bat" "C:\Users\Admin\AppData\Local\Temp\6f9bed90c1d6df1c7b259f832130b5fef5e0d0c9dc6c2564dad53dc0ca30bb0e_unpacked.dll""
  2⤵
  - Suspicious use of WriteProcessMemory
  PID:1484
- - C:\Windows\system32\attrib.exe
    attrib -s -r -h "C:\Users\Admin\AppData\Local\Temp\6f9bed90c1d6df1c7b259f832130b5fef5e0d0c9dc6c2564dad53dc0ca30bb0e_unpacked.dll"
    3⤵
    - Views/modifies file attributes
    PID:4680

Network

MITRE ATT&CK Enterprise v6

Initial Access

Execution

Persistence

Hidden Files and Directories

1

T1158

Privilege Escalation

Defense Evasion

Hidden Files and Directories

1

T1158

Credential Access

Discovery

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

C:\Recovery\WindowsRE\RecoveryManual.html

Filesize
2KB

MD5
ad33271c32be7b98e37d34b19c7aabdb

SHA1
c64f3634526348da465475692f72ec2a59164b59

SHA256
792533ff6d829266c541990c66dae5a66fb5bdd8feb44424409f453c47cb221d

SHA512
73d994467891e0a76894063e8ddba1c8d5c21c03271a9bc5eddc1461883732914df098cc494f918f79cafca13d804f3c450097d64d7d0d283c159fbf6cf82b4e

Download Submit
C:\Users\Admin\AppData\Local\Temp\0E572CAD.bat

Filesize
65B

MD5
348cae913e496198548854f5ff2f6d1e

SHA1
a07655b9020205bd47084afd62a8bb22b48c0cdc

SHA256
c80128f51871eec3ae2057989a025ce244277c1c180498a5aaef45d5214b8506

SHA512
799796736d41d3fcb5a7c859571bb025ca2d062c4b86e078302be68c1a932ed4f78e003640df5405274364b5a9a9c0ba5e37177997683ee7ab54e5267590b611

Download Submit

Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Enterprise v6

Replay Monitor

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Downloads