remcos | fd1f22bc2ba7e424aefb96a8871bb40f1b051e4e2620ad1d9e00347e521e671f

General

Target

msimg32.dll
Size

2.9MB
MD5

abd99b6d60ee5d44f0e5448d3947b281
SHA1

ef799bbe58d3d576e9e27e60e17e071725c975d8
SHA256

5b1aa2286d1b856ce45fc1bf075f36454aaac664460afb91185c4cc451291b62
SHA512

faf79a91f57c1e1c863e75614c0f4c9fb0acabdf7d4097c1554f09e1aef14f8efc0de3bc4261f3728da77fc548878532ceb1f76a1db1df485fcc10772419379c
SSDEEP

49152:hk8XGHSOdOoyWzL/bI7UAnuqSrtdBDmfKtTaeBiDw0uv+Kx55+v0UbpeQM/TNSWs:XGy0FfDEUYuqSvBDmS3YDw0+eha78

Score

10^/10

remcos remotehost discovery persistence rat

Malware Config

Extracted

Family

remcos

Botnet

RemoteHost

C2

privmerkt.com:6042

Attributes

audio_folder
MicRecords
audio_record_time
5
connect_delay
0
connect_interval
1
copy_file
remcos.exe
copy_folder
Remcos
delete_file
false
hide_file
false
hide_keylog_file
false
install_flag
false
keylog_crypt
false
keylog_file
logs.dat
keylog_flag
false
keylog_folder
remcos
mouse_option
false
mutex
Rmc-XE94AK
screenshot_crypt
false
screenshot_flag
false
screenshot_folder
Screenshots
screenshot_path
%AppData%
screenshot_time
10
take_screenshot_option
false
take_screenshot_time
5

Signatures

Remcos
Remcos is a closed-source remote control and surveillance software.
rat remcos

Blocklisted process makes network request 2 IoCs

flow	pid	Process
22	3736	rundll32.exe
25	3736	rundll32.exe

Adds Run key to start application 2 TTPs 1 IoCs

persistence

Registry Run Keys / Startup Folder

T1547.001

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\USER\S-1-5-21-1194130065-3471212556-1656947724-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\*ChromeUpdate = "rundll32.exe C:\\Users\\Admin\\Documents\\FirefoxData.dll,EntryPoint"	reg.exe

Suspicious use of NtCreateThreadExHideFromDebugger 1 IoCs

pid	Process
4844	rundll32.exe

System Location Discovery: System Language Discovery 1 TTPs 4 IoCs

Attempt gather information about the system language of a victim in order to infer the geographical location of that host.

discovery

System Language Discovery

T1614.001

description	ioc	Process
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	cmd.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	reg.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	rundll32.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	rundll32.exe

Suspicious use of WriteProcessMemory 15 IoCs

description	pid	Process	procid_target
PID 3708 wrote to memory of 4844	3708	rundll32.exe	84
PID 3708 wrote to memory of 4844	3708	rundll32.exe	84
PID 3708 wrote to memory of 4844	3708	rundll32.exe	84
PID 4844 wrote to memory of 3736	4844	rundll32.exe	92
PID 4844 wrote to memory of 3736	4844	rundll32.exe	92
PID 4844 wrote to memory of 3736	4844	rundll32.exe	92
PID 4844 wrote to memory of 3736	4844	rundll32.exe	92
PID 4844 wrote to memory of 3736	4844	rundll32.exe	92
PID 4844 wrote to memory of 3736	4844	rundll32.exe	92
PID 4844 wrote to memory of 2580	4844	rundll32.exe	93
PID 4844 wrote to memory of 2580	4844	rundll32.exe	93
PID 4844 wrote to memory of 2580	4844	rundll32.exe	93
PID 2580 wrote to memory of 3360	2580	cmd.exe	95
PID 2580 wrote to memory of 3360	2580	cmd.exe	95
PID 2580 wrote to memory of 3360	2580	cmd.exe	95

C:\Windows\system32\rundll32.exe
rundll32.exe C:\Users\Admin\AppData\Local\Temp\msimg32.dll,#1
1⤵
- Suspicious use of WriteProcessMemory
PID:3708
- C:\Windows\SysWOW64\rundll32.exe
  rundll32.exe C:\Users\Admin\AppData\Local\Temp\msimg32.dll,#1
  2⤵
  - Suspicious use of NtCreateThreadExHideFromDebugger
  - System Location Discovery: System Language Discovery
  - Suspicious use of WriteProcessMemory
  PID:4844
- - C:\Windows\SysWOW64\rundll32.exe
    "C:\Windows\SysWOW64\rundll32.exe"
    3⤵
    - Blocklisted process makes network request
    - System Location Discovery: System Language Discovery
    PID:3736
- - C:\Windows\SysWOW64\cmd.exe
    cmd.exe /C reg add "HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" /v "*ChromeUpdate" /t REG_SZ /d "rundll32.exe C:\Users\Admin\Documents\FirefoxData.dll",EntryPoint /f & exit
    3⤵
    - System Location Discovery: System Language Discovery
    - Suspicious use of WriteProcessMemory
    PID:2580
  - - C:\Windows\SysWOW64\reg.exe
      reg add "HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" /v "*ChromeUpdate" /t REG_SZ /d "rundll32.exe C:\Users\Admin\Documents\FirefoxData.dll",EntryPoint /f
      4⤵
      Adds Run key to start application
      System Location Discovery: System Language Discovery
      PID:3360

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Persistence

Boot or Logon Autostart Execution

1

T1547

Registry Run Keys / Startup Folder

1

T1547.001

Privilege Escalation

Boot or Logon Autostart Execution

1

T1547

Registry Run Keys / Startup Folder

1

T1547.001

Defense Evasion

Modify Registry

1

T1112

Credential Access

Discovery

System Location Discovery

1

T1614

System Language Discovery

1

T1614.001

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

memory/3736-14-0x0000000000AA0000-0x0000000000B22000-memory.dmp

Filesize
520KB

Download
memory/3736-24-0x0000000000AA0000-0x0000000000B22000-memory.dmp

Filesize
520KB

Download
memory/3736-13-0x0000000000AA0000-0x0000000000B22000-memory.dmp

Filesize
520KB

Download
memory/3736-30-0x0000000000AA0000-0x0000000000B22000-memory.dmp

Filesize
520KB

Download
memory/3736-5-0x0000000000B30000-0x0000000000B31000-memory.dmp

Filesize
4KB

Download
memory/3736-12-0x0000000000AA0000-0x0000000000B22000-memory.dmp

Filesize
520KB

Download
memory/3736-11-0x0000000000AA0000-0x0000000000B22000-memory.dmp

Filesize
520KB

Download
memory/3736-10-0x0000000000AA0000-0x0000000000B22000-memory.dmp

Filesize
520KB

Download
memory/3736-23-0x0000000000AA0000-0x0000000000B22000-memory.dmp

Filesize
520KB

Download
memory/3736-22-0x0000000000AA0000-0x0000000000B22000-memory.dmp

Filesize
520KB

Download
memory/3736-31-0x0000000000AA0000-0x0000000000B22000-memory.dmp

Filesize
520KB

Download
memory/3736-21-0x0000000000AA0000-0x0000000000B22000-memory.dmp

Filesize
520KB

Download
memory/3736-16-0x0000000000AA0000-0x0000000000B22000-memory.dmp

Filesize
520KB

Download
memory/3736-15-0x0000000000AA0000-0x0000000000B22000-memory.dmp

Filesize
520KB

Download
memory/3736-19-0x0000000000AA0000-0x0000000000B22000-memory.dmp

Filesize
520KB

Download
memory/3736-17-0x0000000000AA0000-0x0000000000B22000-memory.dmp

Filesize
520KB

Download
memory/4844-1-0x000000001000E000-0x0000000010028000-memory.dmp

Filesize
104KB

Download
memory/4844-20-0x000000001000E000-0x0000000010028000-memory.dmp

Filesize
104KB

Download
memory/4844-3-0x0000000010000000-0x00000000102EF000-memory.dmp

Filesize
2.9MB

Download
memory/4844-4-0x0000000010000000-0x00000000102EF000-memory.dmp

Filesize
2.9MB

Download
memory/4844-7-0x0000000010000000-0x00000000102EF000-memory.dmp

Filesize
2.9MB

Download
memory/4844-2-0x0000000010000000-0x00000000102EF000-memory.dmp

Filesize
2.9MB

Download
memory/4844-9-0x0000000010000000-0x00000000102EF000-memory.dmp

Filesize
2.9MB

Download
memory/4844-0-0x0000000010000000-0x00000000102EF000-memory.dmp

Filesize
2.9MB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads