mountlocker | 189d48b6da8b247fb15f6b1021f668a8bc6739965de8dbf7cab9698478e8c2a2

Analysis

max time kernel
120s
max time network
123s
platform
windows7_x64
resource
win7-20240221-en
resource tags

arch:x64arch:x86image:win7-20240221-enlocale:en-usos:windows7-x64system
submitted
05/03/2024, 17:09

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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

Malware Config

Signatures

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

Deletes itself 1 IoCs

pid	Process
2336	cmd.exe

Drops desktop.ini file(s) 32 IoCs

description	ioc	Process
File opened for modification	\??\c:\Users\Admin\Searches\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Public\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Public\Downloads\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Public\Recorded TV\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 for United States\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Favorites\Links\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Public\Music\Sample Music\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\AppData\Local\Microsoft\Feeds Cache\8YA80BVK\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Public\Pictures\Sample Pictures\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\AppData\Local\Microsoft\Feeds Cache\QBK2VD81\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Music\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Pictures\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Public\Libraries\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\AppData\Local\Microsoft\Feeds Cache\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Downloads\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\Videos\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Public\Videos\Sample Videos\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\AppData\Local\Microsoft\Feeds Cache\MSUBLQZS\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\AppData\Local\Microsoft\Windows Mail\Stationery\Desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Favorites\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\Public\Recorded TV\Sample Media\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\AppData\Local\Microsoft\Feeds Cache\TRGSE1EV\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Documents\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Public\Music\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Contacts\desktop.ini	rundll32.exe
File opened for modification	\??\c:\Users\Admin\Links\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 3 IoCs

description	ioc	Process
File created	\??\c:\Program Files\RecoveryManual.html	rundll32.exe
File created	\??\c:\Program Files (x86)\RecoveryManual.html	rundll32.exe
File created	\??\c:\Program Files (x86)\Microsoft SQL Server Compact Edition\v3.5\RecoveryManual.html	rundll32.exe

Modifies registry class 5 IoCs

description	ioc	Process
Key created	\REGISTRY\USER\S-1-5-21-778096762-2241304387-192235952-1000_CLASSES\.965F9BB4	rundll32.exe
Key created	\REGISTRY\USER\S-1-5-21-778096762-2241304387-192235952-1000_CLASSES\.965F9BB4\shell	rundll32.exe
Key created	\REGISTRY\USER\S-1-5-21-778096762-2241304387-192235952-1000_CLASSES\.965F9BB4\shell\Open	rundll32.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-778096762-2241304387-192235952-1000_CLASSES\.965F9BB4\shell\Open\command\ = "explorer.exe RecoveryManual.html"	rundll32.exe
Key created	\REGISTRY\USER\S-1-5-21-778096762-2241304387-192235952-1000_CLASSES\.965F9BB4\shell\Open\command	rundll32.exe

Suspicious behavior: EnumeratesProcesses 2 IoCs

pid	Process
2868	rundll32.exe
2868	rundll32.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

description	pid	Process
Token: SeRestorePrivilege	2868	rundll32.exe
Token: SeDebugPrivilege	2868	rundll32.exe

Suspicious use of WriteProcessMemory 15 IoCs

description	pid	Process	procid_target
PID 2088 wrote to memory of 2868	2088	rundll32.exe	28
PID 2088 wrote to memory of 2868	2088	rundll32.exe	28
PID 2088 wrote to memory of 2868	2088	rundll32.exe	28
PID 2088 wrote to memory of 2868	2088	rundll32.exe	28
PID 2088 wrote to memory of 2868	2088	rundll32.exe	28
PID 2088 wrote to memory of 2868	2088	rundll32.exe	28
PID 2088 wrote to memory of 2868	2088	rundll32.exe	28
PID 2868 wrote to memory of 2336	2868	rundll32.exe	30
PID 2868 wrote to memory of 2336	2868	rundll32.exe	30
PID 2868 wrote to memory of 2336	2868	rundll32.exe	30
PID 2868 wrote to memory of 2336	2868	rundll32.exe	30
PID 2336 wrote to memory of 1500	2336	cmd.exe	32
PID 2336 wrote to memory of 1500	2336	cmd.exe	32
PID 2336 wrote to memory of 1500	2336	cmd.exe	32
PID 2336 wrote to memory of 1500	2336	cmd.exe	32

Views/modifies file attributes 1 TTPs 1 IoCs

evasion

Hidden Files and Directories

T1564.001

pid	Process
1500	attrib.exe

C:\Windows\system32\rundll32.exe
rundll32.exe C:\Users\Admin\AppData\Local\Temp\b538015bcbdaa4a8997b45f88add38be.dll,#1
1⤵
- Suspicious use of WriteProcessMemory
PID:2088
- 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:2868
- - C:\Windows\SysWOW64\cmd.exe
    cmd /c ""C:\Users\Admin\AppData\Local\Temp\\0F769186.bat" "C:\Users\Admin\AppData\Local\Temp\b538015bcbdaa4a8997b45f88add38be.dll""
    3⤵
    - Deletes itself
    - Suspicious use of WriteProcessMemory
    PID:2336
  - - C:\Windows\SysWOW64\attrib.exe
      attrib -s -r -h "C:\Users\Admin\AppData\Local\Temp\b538015bcbdaa4a8997b45f88add38be.dll"
      4⤵
      Views/modifies file attributes
      PID:1500

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Persistence

Privilege Escalation

Defense Evasion

Hide Artifacts

T1564

Hidden Files and Directories

T1564.001

Credential Access

Discovery

Peripheral Device Discovery

T1120

Query Registry

T1012

System Information Discovery

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Replay Monitor

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Downloads

C:\MSOCache\All Users\{90140000-001A-0409-0000-0000000FF1CE}-C\RecoveryManual.html

Filesize
2KB

MD5
d537786b7b868a450b1ef3edf09b2b91

SHA1
9f0478525577b66601a0ebe8eead0d17d17d8ef5

SHA256
2c21e959939c374a792f5fa6f3674aafee6845f409503185b7569a10e89821a8

SHA512
f46534d0d65bf8300efac71c44fbb27c8e29e68094eb358ad633b463bac0ef5fb3f69c15d700f0757c1488c64f86839539add12e3517cf3d43be68c685f6bc44

Download Submit
C:\Users\Admin\AppData\Local\Temp\0F769186.bat

Filesize
65B

MD5
348cae913e496198548854f5ff2f6d1e

SHA1
a07655b9020205bd47084afd62a8bb22b48c0cdc

SHA256
c80128f51871eec3ae2057989a025ce244277c1c180498a5aaef45d5214b8506

SHA512
799796736d41d3fcb5a7c859571bb025ca2d062c4b86e078302be68c1a932ed4f78e003640df5405274364b5a9a9c0ba5e37177997683ee7ab54e5267590b611

Download Submit
memory/2868-15-0x0000000000900000-0x00000000009C6000-memory.dmp

Filesize
792KB

Download
memory/2868-30-0x0000000000900000-0x00000000009C6000-memory.dmp

Filesize
792KB

Download
memory/2868-4-0x0000000000900000-0x00000000009C6000-memory.dmp

Filesize
792KB

Download
memory/2868-2-0x0000000000900000-0x00000000009C6000-memory.dmp

Filesize
792KB

Download
memory/2868-17-0x0000000000900000-0x00000000009C6000-memory.dmp

Filesize
792KB

Download
memory/2868-16-0x0000000000900000-0x00000000009C6000-memory.dmp

Filesize
792KB

Download
memory/2868-0-0x0000000000900000-0x00000000009C6000-memory.dmp

Filesize
792KB

Download
memory/2868-5-0x0000000000900000-0x00000000009C6000-memory.dmp

Filesize
792KB

Download
memory/2868-13-0x0000000000900000-0x00000000009C6000-memory.dmp

Filesize
792KB

Download
memory/2868-456-0x0000000000900000-0x00000000009C6000-memory.dmp

Filesize
792KB

Download
memory/2868-565-0x0000000000900000-0x00000000009C6000-memory.dmp

Filesize
792KB

Download
memory/2868-567-0x0000000000900000-0x00000000009C6000-memory.dmp

Filesize
792KB

Download
memory/2868-1-0x0000000000900000-0x00000000009C6000-memory.dmp

Filesize
792KB

Download
memory/2868-576-0x0000000000900000-0x00000000009C6000-memory.dmp

Filesize
792KB

Download