mountlocker | 189d48b6da8b247fb15f6b1021f668a8bc6739965de8dbf7cab9698478e8c2a2

General

Target

b538015bcbdaa4a8997b45f88add38be.dll
Size

180KB
MD5

b538015bcbdaa4a8997b45f88add38be
SHA1

84842a36447d2a205d60cfa4c06fe9b6f69f2d03
SHA256

189d48b6da8b247fb15f6b1021f668a8bc6739965de8dbf7cab9698478e8c2a2
SHA512

02859c8cfd4cf08ebfa8440607c0b58c6b27d4c08a97ed9a81df5251ee46826a3edf137e3ec85c539ed262c39e9954a6a4b91f3ee4400017c9b054bcb5018ad3
SSDEEP

1536:bIYmy/vfY+0Q1sLoCaRL5YLnQVhLZB2aBoucf09mxdGyk161KpoPvHWfkV76htLK:nhLm0LZKbf9Eykpp4ff76LLK

Score

10^/10

mountlocker ransomware spyware stealer

Malware Config

Signatures

MountLocker Ransomware
Ransomware family first seen in late 2020, which threatens to leak files if ransom is not paid.
ransomware mountlocker
Reads user/profile data of web browsers 2 TTPs
Infostealers often target stored browser data, which can include saved credentials etc.
spyware stealer

Data from Local System
T1005

Credentials In Files
T1552.001

Drops desktop.ini file(s) 25 IoCs

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

Enumerates connected drives 3 TTPs 1 IoCs

Attempts to read the root path of hard drives other than the default C: drive.

Query Registry

T1012

Peripheral Device Discovery

T1120

System Information Discovery

T1082

description	ioc	Process
File opened (read-only)	\??\f:	rundll32.exe

Drops file in Program Files directory 2 IoCs

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

description	ioc	Process
Set value (str)	\REGISTRY\USER\S-1-5-21-557049126-2506969350-2798870634-1000_Classes\.965F9BB4\shell\Open\command\ = "explorer.exe RecoveryManual.html"	rundll32.exe
Key created	\REGISTRY\USER\S-1-5-21-557049126-2506969350-2798870634-1000_Classes\.965F9BB4\shell\Open\command	rundll32.exe
Key created	\REGISTRY\USER\S-1-5-21-557049126-2506969350-2798870634-1000_Classes\.965F9BB4	rundll32.exe
Key created	\REGISTRY\USER\S-1-5-21-557049126-2506969350-2798870634-1000_Classes\.965F9BB4\shell	rundll32.exe
Key created	\REGISTRY\USER\S-1-5-21-557049126-2506969350-2798870634-1000_Classes\.965F9BB4\shell\Open	rundll32.exe

Suspicious behavior: EnumeratesProcesses 2 IoCs

pid	Process
3684	rundll32.exe
3684	rundll32.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeRestorePrivilege	3684	rundll32.exe
Token: SeDebugPrivilege	3684	rundll32.exe

Suspicious use of WriteProcessMemory 9 IoCs

description	pid	Process	procid_target
PID 908 wrote to memory of 3684	908	rundll32.exe	87
PID 908 wrote to memory of 3684	908	rundll32.exe	87
PID 908 wrote to memory of 3684	908	rundll32.exe	87
PID 3684 wrote to memory of 1912	3684	rundll32.exe	92
PID 3684 wrote to memory of 1912	3684	rundll32.exe	92
PID 3684 wrote to memory of 1912	3684	rundll32.exe	92
PID 1912 wrote to memory of 4668	1912	cmd.exe	96
PID 1912 wrote to memory of 4668	1912	cmd.exe	96
PID 1912 wrote to memory of 4668	1912	cmd.exe	96

Views/modifies file attributes 1 TTPs 1 IoCs

evasion

Hidden Files and Directories

T1564.001

pid	Process
4668	attrib.exe

C:\Windows\system32\rundll32.exe
rundll32.exe C:\Users\Admin\AppData\Local\Temp\b538015bcbdaa4a8997b45f88add38be.dll,#1
1⤵
- Suspicious use of WriteProcessMemory
PID:908
- C:\Windows\SysWOW64\rundll32.exe
  rundll32.exe C:\Users\Admin\AppData\Local\Temp\b538015bcbdaa4a8997b45f88add38be.dll,#1
  2⤵
  - Drops desktop.ini file(s)
  - Enumerates connected drives
  - Drops file in Program Files directory
  - Modifies registry class
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of AdjustPrivilegeToken
  - Suspicious use of WriteProcessMemory
  PID:3684
- - C:\Windows\SysWOW64\cmd.exe
    C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\\0E57AD76.bat" "C:\Users\Admin\AppData\Local\Temp\b538015bcbdaa4a8997b45f88add38be.dll""
    3⤵
    - Suspicious use of WriteProcessMemory
    PID:1912
  - - C:\Windows\SysWOW64\attrib.exe
      attrib -s -r -h "C:\Users\Admin\AppData\Local\Temp\b538015bcbdaa4a8997b45f88add38be.dll"
      4⤵
      Views/modifies file attributes
      PID:4668

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Persistence

Privilege Escalation

Defense Evasion

Hide Artifacts

1

T1564

Hidden Files and Directories

1

T1564.001

Credential Access

Unsecured Credentials

1

T1552

Credentials In Files

1

T1552.001

Discovery

Peripheral Device Discovery

Query Registry

System Information Discovery

1

T1082

Lateral Movement

Collection

Data from Local System

1

T1005

Command and Control

Exfiltration

Impact

Replay Monitor

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Downloads

C:\Recovery\WindowsRE\RecoveryManual.html

Filesize
2KB

MD5
50ba84406e6088fedfb6ef20251c727b

SHA1
9c919e6d5e8427bb4f7576a26a17248d3607931f

SHA256
6d45903f502b8f9ce0dfd95ca3b907c3e3555f37540d9366cc90d7586d3a5684

SHA512
39c8d133e6420bbaccff123e39559e3868ff0ef6a0a71b2fc1c2964ce52503e63a22cc2b02b91a6d5a3f9aa7a916ab4b1f42a43ac3c73804d077abdc6d1c4974

Download Submit
C:\Users\Admin\AppData\Local\Temp\0E57AD76.bat

Filesize
65B

MD5
348cae913e496198548854f5ff2f6d1e

SHA1
a07655b9020205bd47084afd62a8bb22b48c0cdc

SHA256
c80128f51871eec3ae2057989a025ce244277c1c180498a5aaef45d5214b8506

SHA512
799796736d41d3fcb5a7c859571bb025ca2d062c4b86e078302be68c1a932ed4f78e003640df5405274364b5a9a9c0ba5e37177997683ee7ab54e5267590b611

Download Submit
memory/3684-82-0x0000000000C90000-0x0000000000D56000-memory.dmp

Filesize
792KB

Download
memory/3684-5-0x0000000000C90000-0x0000000000D56000-memory.dmp

Filesize
792KB

Download
memory/3684-46-0x0000000000C90000-0x0000000000D56000-memory.dmp

Filesize
792KB

Download
memory/3684-10-0x0000000000C90000-0x0000000000D56000-memory.dmp

Filesize
792KB

Download
memory/3684-0-0x0000000000C90000-0x0000000000D56000-memory.dmp

Filesize
792KB

Download
memory/3684-83-0x0000000000C90000-0x0000000000D56000-memory.dmp

Filesize
792KB

Download
memory/3684-3-0x0000000000C90000-0x0000000000D56000-memory.dmp

Filesize
792KB

Download
memory/3684-1131-0x0000000000C90000-0x0000000000D56000-memory.dmp

Filesize
792KB

Download
memory/3684-1134-0x0000000000C90000-0x0000000000D56000-memory.dmp

Filesize
792KB

Download
memory/3684-1-0x0000000000C90000-0x0000000000D56000-memory.dmp

Filesize
792KB

Download
memory/3684-1141-0x0000000000C90000-0x0000000000D56000-memory.dmp

Filesize
792KB

Download

Analysis

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