mountlocker | 4a5ac3c6f8383cc33c795804ba5f7f5553c029bbb4a6d28f1e4d8fb5107902c1

General

Target

xxxx.exe
Size

66KB
MD5

3808f21e56dede99bc914d90aeabe47a
SHA1

93cc73149d4bb34830a2cb2a3047e9267b9e3080
SHA256

4a5ac3c6f8383cc33c795804ba5f7f5553c029bbb4a6d28f1e4d8fb5107902c1
SHA512

4ae55145cca3a6f1ed3feff5b2bd38121e37c4cc528e08d5de771bcc4855994560bfc8c22898d73c5b259e37d2dc803615b8f6ec859e53918bd7a1ffee9316b3

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 7 IoCs

Ransomware generally changes the extension on encrypted files.

ransomware

Processes:

xxxx.exe

description	ioc	process
File renamed	C:\Users\Admin\Pictures\SelectMount.png => \??\c:\Users\Admin\Pictures\SelectMount.png.ReadManual.F638D8A0	xxxx.exe
File renamed	C:\Users\Admin\Pictures\StepCompress.tif => \??\c:\Users\Admin\Pictures\StepCompress.tif.ReadManual.F638D8A0	xxxx.exe
File opened for modification	\??\c:\Users\Admin\Pictures\SubmitDismount.tiff	xxxx.exe
File renamed	C:\Users\Admin\Pictures\SubmitDismount.tiff => \??\c:\Users\Admin\Pictures\SubmitDismount.tiff.ReadManual.F638D8A0	xxxx.exe
File renamed	C:\Users\Admin\Pictures\EditCompress.raw => \??\c:\Users\Admin\Pictures\EditCompress.raw.ReadManual.F638D8A0	xxxx.exe
File renamed	C:\Users\Admin\Pictures\LimitRepair.tif => \??\c:\Users\Admin\Pictures\LimitRepair.tif.ReadManual.F638D8A0	xxxx.exe
File renamed	C:\Users\Admin\Pictures\ResetUnpublish.crw => \??\c:\Users\Admin\Pictures\ResetUnpublish.crw.ReadManual.F638D8A0	xxxx.exe

Deletes itself 1 IoCs

Processes:

cmd.exe

pid process

568 cmd.exe

pid	process
568	cmd.exe

Drops desktop.ini file(s) 32 IoCs

Processes:

xxxx.exe

description	ioc	process
File opened for modification	\??\c:\Users\Admin\AppData\Local\Microsoft\Feeds Cache\NU1L7O13\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\Favorites\Links for United States\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\Links\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\AppData\Local\Microsoft\Feeds Cache\VNYR844D\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Public\Recorded TV\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\AppData\Local\Microsoft\Windows Mail\Stationery\Desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\Documents\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\Pictures\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\Searches\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Public\Pictures\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\Favorites\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\Videos\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Public\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Public\Music\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Public\Music\Sample Music\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\AppData\Local\Microsoft\Feeds Cache\H18KNA1T\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\Favorites\Links\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\Saved Games\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Public\Documents\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Public\Recorded TV\Sample Media\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\AppData\Local\Microsoft\Feeds Cache\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\Desktop\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\Music\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Public\Pictures\Sample Pictures\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Public\Videos\Sample Videos\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\AppData\Local\Microsoft\Feeds Cache\E9RC2MV6\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\Contacts\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Admin\Downloads\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Public\Desktop\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Public\Downloads\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Public\Libraries\desktop.ini	xxxx.exe
File opened for modification	\??\c:\Users\Public\Videos\desktop.ini	xxxx.exe

Drops file in Program Files directory 3 IoCs

Processes:

xxxx.exe

description	ioc	process
File created	\??\c:\Program Files\RecoveryManual.html	xxxx.exe
File created	\??\c:\Program Files (x86)\RecoveryManual.html	xxxx.exe
File created	\??\c:\Program Files (x86)\Microsoft SQL Server Compact Edition\v3.5\RecoveryManual.html	xxxx.exe

Modifies registry class 5 IoCs

Processes:

xxxx.exe

description	ioc	process
Key created	\REGISTRY\USER\S-1-5-21-2455352368-1077083310-2879168483-1000_CLASSES\.F638D8A0\shell\Open	xxxx.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-2455352368-1077083310-2879168483-1000_CLASSES\.F638D8A0\shell\Open\command\ = "explorer.exe RecoveryManual.html"	xxxx.exe
Key created	\REGISTRY\USER\S-1-5-21-2455352368-1077083310-2879168483-1000_CLASSES\.F638D8A0\shell\Open\command	xxxx.exe
Key created	\REGISTRY\USER\S-1-5-21-2455352368-1077083310-2879168483-1000_CLASSES\.F638D8A0	xxxx.exe
Key created	\REGISTRY\USER\S-1-5-21-2455352368-1077083310-2879168483-1000_CLASSES\.F638D8A0\shell	xxxx.exe

Suspicious behavior: EnumeratesProcesses 2 IoCs

Processes:

xxxx.exe

pid process

1776 xxxx.exe
1776 xxxx.exe
Suspicious use of AdjustPrivilegeToken 2 IoCs

Processes:

xxxx.exe

description pid process

Token: SeRestorePrivilege 1776 xxxx.exe
Token: SeDebugPrivilege 1776 xxxx.exe

pid	process
1776	xxxx.exe
1776	xxxx.exe

description	pid	process
Token: SeRestorePrivilege	1776	xxxx.exe
Token: SeDebugPrivilege	1776	xxxx.exe

Suspicious use of WriteProcessMemory 6 IoCs

Processes:

xxxx.execmd.exe

description	pid	process	target process
PID 1776 wrote to memory of 568	1776	xxxx.exe	cmd.exe
PID 1776 wrote to memory of 568	1776	xxxx.exe	cmd.exe
PID 1776 wrote to memory of 568	1776	xxxx.exe	cmd.exe
PID 568 wrote to memory of 1716	568	cmd.exe	attrib.exe
PID 568 wrote to memory of 1716	568	cmd.exe	attrib.exe
PID 568 wrote to memory of 1716	568	cmd.exe	attrib.exe

Views/modifies file attributes 1 TTPs 1 IoCs
evasion

Hidden Files and Directories
T1158

Processes:

attrib.exe

pid process

1716 attrib.exe

pid	process
1716	attrib.exe

C:\Users\Admin\AppData\Local\Temp\xxxx.exe
"C:\Users\Admin\AppData\Local\Temp\xxxx.exe"
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:1776
- C:\Windows\system32\cmd.exe
  cmd /c ""C:\Users\Admin\AppData\Local\Temp\\0F74F7A8.bat" "C:\Users\Admin\AppData\Local\Temp\xxxx.exe""
  2⤵
  - Deletes itself
  - Suspicious use of WriteProcessMemory
  PID:568
- - C:\Windows\system32\attrib.exe
    attrib -s -r -h "C:\Users\Admin\AppData\Local\Temp\xxxx.exe"
    3⤵
    - Views/modifies file attributes
    PID:1716

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:\Users\Admin\AppData\Local\Temp\0F74F7A8.bat

MD5
348cae913e496198548854f5ff2f6d1e

SHA1
a07655b9020205bd47084afd62a8bb22b48c0cdc

SHA256
c80128f51871eec3ae2057989a025ce244277c1c180498a5aaef45d5214b8506

SHA512
799796736d41d3fcb5a7c859571bb025ca2d062c4b86e078302be68c1a932ed4f78e003640df5405274364b5a9a9c0ba5e37177997683ee7ab54e5267590b611

Download Submit
memory/568-60-0x0000000000000000-mapping.dmp

Download
memory/1716-62-0x0000000000000000-mapping.dmp

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Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Enterprise v6

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