remcos | d1f85945fa3f402202ed31fc7322c3328676a1d609fc9c17ee3a3cb6a49aa5fb

General

Target

unknown.exe
Size

38KB
MD5

66c49b26cf4da200e05a814cedfc3e83
SHA1

b211205b3a1cc3219e0c877ee44e913aa05a1f5c
SHA256

d1f85945fa3f402202ed31fc7322c3328676a1d609fc9c17ee3a3cb6a49aa5fb
SHA512

00208831a6c7583106f08cccc496fd02e7ff4260a2fca1dea4f619878b2179e9fe39cc59d45903efb20914d1cb242a8deac26c83e73e9b1b6823dd52ac759416
SSDEEP

768:E2nsAHG6hbA/RzFxRXmVIjfHI/JfLQT4r1:EYTdm3RXKofyR+4r

Score

10^/10

remcos host discovery persistence rat upx

Malware Config

Extracted

Family

remcos

Version

1.7.3 Pro

Botnet

Host

C2

remcos2.legacyrealestateadvisors.net:30042

remcos.legacyrealestateadvisors.net:30041

Attributes

audio_folder
audio
audio_path
%AppData%
audio_record_time
5
connect_delay
0
connect_interval
5
copy_file
AudioHD.exe
copy_folder
AudioHD
delete_file
false
hide_file
false
hide_keylog_file
true
install_flag
true
install_path
%ProgramFiles%
keylog_crypt
false
keylog_file
Drivers.dat
keylog_flag
false
keylog_folder
AudioHD
keylog_path
%ProgramFiles%
mouse_option
false
mutex
KJSBIuibidbiwee-ZJFN94
screenshot_crypt
false
screenshot_flag
false
screenshot_folder
Screens
screenshot_path
%AppData%
screenshot_time
1
startup_value
AudioHD
take_screenshot_option
false
take_screenshot_time
5

Signatures

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

Checks computer location settings 2 TTPs 1 IoCs

Looks up country code configured in the registry, likely geofence.

Query Registry

T1012

System Information Discovery

T1082

description	ioc	Process
Key value queried	\REGISTRY\USER\S-1-5-21-1194130065-3471212556-1656947724-1000\Control Panel\International\Geo\Nation	unknown.exe

Executes dropped EXE 1 IoCs

pid	Process
4744	AudioHD.exe

UPX packed file 5 IoCs

Detects executables packed with UPX/modified UPX open source packer.

upx

resource	yara_rule
behavioral2/memory/4564-0-0x0000000000400000-0x000000000041F000-memory.dmp	upx
behavioral2/memory/4564-5-0x0000000000400000-0x000000000041F000-memory.dmp	upx
behavioral2/files/0x00090000000234c1-8.dat	upx
behavioral2/memory/4516-10-0x0000000000400000-0x000000000041F000-memory.dmp	upx
behavioral2/memory/4744-12-0x0000000000400000-0x000000000041F000-memory.dmp	upx

Adds Run key to start application 2 TTPs 2 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\AudioHD = "\"C:\\Program Files (x86)\\AudioHD\\AudioHD.exe\""	unknown.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-1194130065-3471212556-1656947724-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\AudioHD = "\"C:\\Program Files (x86)\\AudioHD\\AudioHD.exe\""	AudioHD.exe

Suspicious use of SetThreadContext 1 IoCs

description	pid	Process	procid_target
PID 4744 set thread context of 4516	4744	AudioHD.exe	86

Drops file in Program Files directory 2 IoCs

description	ioc	Process
File created	C:\Program Files (x86)\AudioHD\AudioHD.exe	unknown.exe
File opened for modification	C:\Program Files (x86)\AudioHD\AudioHD.exe	unknown.exe

Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s).

System Information Discovery
T1082

Program crash 2 IoCs

pid	pid_target	Process	procid_target
3148	4516	WerFault.exe	86
4916	4744	WerFault.exe	85

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	unknown.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	cmd.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	PING.EXE
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	AudioHD.exe

System Network Configuration Discovery: Internet Connection Discovery 1 TTPs 1 IoCs

Adversaries may check for Internet connectivity on compromised systems.

discovery

Internet Connection Discovery

T1016.001

pid	Process
4820	PING.EXE

Runs ping.exe 1 TTPs 1 IoCs

Remote System Discovery

T1018

pid	Process
4820	PING.EXE

Suspicious use of SetWindowsHookEx 1 IoCs

pid	Process
4744	AudioHD.exe

Suspicious use of WriteProcessMemory 17 IoCs

description	pid	Process	procid_target
PID 4564 wrote to memory of 1124	4564	unknown.exe	82
PID 4564 wrote to memory of 1124	4564	unknown.exe	82
PID 4564 wrote to memory of 1124	4564	unknown.exe	82
PID 1124 wrote to memory of 4820	1124	cmd.exe	84
PID 1124 wrote to memory of 4820	1124	cmd.exe	84
PID 1124 wrote to memory of 4820	1124	cmd.exe	84
PID 1124 wrote to memory of 4744	1124	cmd.exe	85
PID 1124 wrote to memory of 4744	1124	cmd.exe	85
PID 1124 wrote to memory of 4744	1124	cmd.exe	85
PID 4744 wrote to memory of 4516	4744	AudioHD.exe	86
PID 4744 wrote to memory of 4516	4744	AudioHD.exe	86
PID 4744 wrote to memory of 4516	4744	AudioHD.exe	86
PID 4744 wrote to memory of 4516	4744	AudioHD.exe	86
PID 4744 wrote to memory of 4516	4744	AudioHD.exe	86
PID 4744 wrote to memory of 4516	4744	AudioHD.exe	86
PID 4744 wrote to memory of 4516	4744	AudioHD.exe	86
PID 4744 wrote to memory of 4516	4744	AudioHD.exe	86

C:\Users\Admin\AppData\Local\Temp\unknown.exe
"C:\Users\Admin\AppData\Local\Temp\unknown.exe"
1⤵
- Checks computer location settings
- Adds Run key to start application
- Drops file in Program Files directory
- System Location Discovery: System Language Discovery
- Suspicious use of WriteProcessMemory
PID:4564
- C:\Windows\SysWOW64\cmd.exe
  C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\install.bat" "
  2⤵
  - System Location Discovery: System Language Discovery
  - Suspicious use of WriteProcessMemory
  PID:1124
- - C:\Windows\SysWOW64\PING.EXE
    PING 127.0.0.1 -n 2
    3⤵
    - System Location Discovery: System Language Discovery
    - System Network Configuration Discovery: Internet Connection Discovery
    - Runs ping.exe
    PID:4820
- - C:\Program Files (x86)\AudioHD\AudioHD.exe
    "C:\Program Files (x86)\AudioHD\AudioHD.exe"
    3⤵
    - Executes dropped EXE
    - Adds Run key to start application
    - Suspicious use of SetThreadContext
    - System Location Discovery: System Language Discovery
    - Suspicious use of SetWindowsHookEx
    - Suspicious use of WriteProcessMemory
    PID:4744
  - - C:\Windows\SysWOW64\svchost.exe
      C:\Windows\SysWOW64\svchost.exe
      4⤵
      PID:4516
    - - C:\Windows\SysWOW64\WerFault.exe
        
        C:\Windows\SysWOW64\WerFault.exe -u -p 4516 -s 192
        5⤵
        Program crash
        
        PID:3148
  - - C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 4744 -s 652
      4⤵
      Program crash
      PID:4916

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 424 -p 4516 -ip 4516
1⤵
PID:4144

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 184 -p 4744 -ip 4744
1⤵
PID:4776

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

Query Registry

1

T1012

Remote System Discovery

1

T1018

System Information Discovery

2

T1082

System Location Discovery

1

T1614

System Language Discovery

1

T1614.001

System Network Configuration Discovery

1

T1016

Internet Connection Discovery

1

T1016.001

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

C:\Program Files (x86)\AudioHD\AudioHD.exe

Filesize
38KB

MD5
66c49b26cf4da200e05a814cedfc3e83

SHA1
b211205b3a1cc3219e0c877ee44e913aa05a1f5c

SHA256
d1f85945fa3f402202ed31fc7322c3328676a1d609fc9c17ee3a3cb6a49aa5fb

SHA512
00208831a6c7583106f08cccc496fd02e7ff4260a2fca1dea4f619878b2179e9fe39cc59d45903efb20914d1cb242a8deac26c83e73e9b1b6823dd52ac759416

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

Filesize
93B

MD5
bf46e6384d13e9ff4a4f3446c2931498

SHA1
45e58330d25ceeda0d8f1cfd03ac37350226c421

SHA256
f86c81ebe796e762831913cf548c170d953f140b5f85022a5d69d190782ca80d

SHA512
894d1c8b3325df87f1ef86200ee0bc19e6eabefcdb4b3fcf3787806f870879389a0d2961154c2381f197213f72203533b21eaae7a9c9d034f783af1d8c657ae7

Download Submit
memory/4516-10-0x0000000000400000-0x000000000041F000-memory.dmp

Filesize
124KB

Download
memory/4564-0-0x0000000000400000-0x000000000041F000-memory.dmp

Filesize
124KB

Download
memory/4564-5-0x0000000000400000-0x000000000041F000-memory.dmp

Filesize
124KB

Download
memory/4744-12-0x0000000000400000-0x000000000041F000-memory.dmp

Filesize
124KB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads