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 2 IoCs

Ransomware generally changes the extension on encrypted files.

ransomware

description	ioc	Process
File renamed	C:\Users\Admin\Pictures\ExportBlock.raw => \??\c:\Users\Admin\Pictures\ExportBlock.raw.ReadManual.F638D8A0	xxxx.exe
File renamed	C:\Users\Admin\Pictures\SelectUnpublish.crw => \??\c:\Users\Admin\Pictures\SelectUnpublish.crw.ReadManual.F638D8A0	xxxx.exe

Drops desktop.ini file(s) 24 IoCs

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

Drops file in Program Files directory 2 IoCs

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

Modifies registry class 5 IoCs

description	ioc	Process
Key created	\REGISTRY\USER\S-1-5-21-3686645723-710336880-414668232-1000_Classes\.F638D8A0\shell\Open\command	xxxx.exe
Key created	\REGISTRY\USER\S-1-5-21-3686645723-710336880-414668232-1000_Classes\.F638D8A0	xxxx.exe
Key created	\REGISTRY\USER\S-1-5-21-3686645723-710336880-414668232-1000_Classes\.F638D8A0\shell	xxxx.exe
Key created	\REGISTRY\USER\S-1-5-21-3686645723-710336880-414668232-1000_Classes\.F638D8A0\shell\Open	xxxx.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3686645723-710336880-414668232-1000_Classes\.F638D8A0\shell\Open\command\ = "explorer.exe RecoveryManual.html"	xxxx.exe

Suspicious behavior: EnumeratesProcesses 2 IoCs

pid	Process
3176	xxxx.exe
3176	xxxx.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeRestorePrivilege	3176	xxxx.exe
Token: SeDebugPrivilege	3176	xxxx.exe

Suspicious use of WriteProcessMemory 4 IoCs

description	pid	Process	procid_target
PID 3176 wrote to memory of 2272	3176	xxxx.exe	78
PID 3176 wrote to memory of 2272	3176	xxxx.exe	78
PID 2272 wrote to memory of 2576	2272	cmd.exe	80
PID 2272 wrote to memory of 2576	2272	cmd.exe	80

Views/modifies file attributes 1 TTPs 1 IoCs

evasion

Hidden Files and Directories

T1158

pid	Process
2576	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:3176
- C:\Windows\system32\cmd.exe
  C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\\0F743A9D.bat" "C:\Users\Admin\AppData\Local\Temp\xxxx.exe""
  2⤵
  - Suspicious use of WriteProcessMemory
  PID:2272
- - C:\Windows\system32\attrib.exe
    attrib -s -r -h "C:\Users\Admin\AppData\Local\Temp\xxxx.exe"
    3⤵
    - Views/modifies file attributes
    PID:2576

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

Analysis

Sharing

General

Malware Config

Signatures

Processes

Network

MITRE ATT&CK Enterprise v6

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