guloader | b42f7b1685c9fa69b07eec4870ae1f573a48ad04c369e452482edbbfed654c24

General

Target

RFQNr.201124559-201124569-201175771.exe
Size

629KB
MD5

ea3570960a117b551ef4d63afb90594a
SHA1

25e8d6660e6bdf88c78a484ecc49f1f5e862902d
SHA256

b42f7b1685c9fa69b07eec4870ae1f573a48ad04c369e452482edbbfed654c24
SHA512

822fd9ae05be68403868ce69aa9944b90d6a3285c8a17d1009cccff02ebd2bc10dc6434cb0473a3e5a5c58c849e3dee112819bf5a6ca395d3447eba65f11d076
SSDEEP

12288:2ZPsXk8zK2u+4rYnH12g+ohTHPU66swKpUHsTx6I+0X:CWhu6H1ZtFPU9skMTxX+0X

Score

10^/10

guloader remcos remotehost discovery downloader rat

Malware Config

Extracted

Family

remcos

Botnet

RemoteHost

C2

191.101.51.117:11371

191.101.51.117:10050

191.101.51.117:10051

191.101.51.117:24554

191.101.51.117:2700

Attributes

audio_folder
MicRecords
audio_path
ApplicationPath
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-XS1JNK
screenshot_crypt
false
screenshot_flag
false
screenshot_folder
Screenshots
screenshot_path
%AppData%
screenshot_time
10
take_screenshot_option
false
take_screenshot_time
5

Signatures

Guloader family
guloader
Guloader,Cloudeye
A shellcode based downloader first seen in 2020.
downloader guloader
Remcos
Remcos is a closed-source remote control and surveillance software.
rat remcos
Remcos family
remcos

Loads dropped DLL 2 IoCs

Processes:

RFQNr.201124559-201124569-201175771.exe

pid	Process
2300	RFQNr.201124559-201124569-201175771.exe
2300	RFQNr.201124559-201124569-201175771.exe

Drops file in System32 directory 1 IoCs

Processes:

RFQNr.201124559-201124569-201175771.exe

description	ioc	Process
File opened for modification	C:\Windows\SysWOW64\gnarrs\tacitness.Spo	RFQNr.201124559-201124569-201175771.exe

Suspicious use of NtCreateThreadExHideFromDebugger 1 IoCs

Processes:

RFQNr.201124559-201124569-201175771.exe

pid	Process
2888	RFQNr.201124559-201124569-201175771.exe

Suspicious use of NtSetInformationThreadHideFromDebugger 2 IoCs

Processes:

RFQNr.201124559-201124569-201175771.exeRFQNr.201124559-201124569-201175771.exe

pid	Process
2300	RFQNr.201124559-201124569-201175771.exe
2888	RFQNr.201124559-201124569-201175771.exe

Suspicious use of SetThreadContext 1 IoCs

Processes:

RFQNr.201124559-201124569-201175771.exe

description	pid	Process	procid_target
PID 2300 set thread context of 2888	2300	RFQNr.201124559-201124569-201175771.exe	89

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

System Information Discovery
T1082

System Location Discovery: System Language Discovery 1 TTPs 2 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

Processes:

RFQNr.201124559-201124569-201175771.exeRFQNr.201124559-201124569-201175771.exe

description	ioc	Process
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	RFQNr.201124559-201124569-201175771.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	RFQNr.201124559-201124569-201175771.exe

Suspicious behavior: MapViewOfSection 1 IoCs

Processes:

RFQNr.201124559-201124569-201175771.exe

pid	Process
2300	RFQNr.201124559-201124569-201175771.exe

Suspicious use of WriteProcessMemory 5 IoCs

Processes:

RFQNr.201124559-201124569-201175771.exe

description	pid	Process	procid_target
PID 2300 wrote to memory of 2888	2300	RFQNr.201124559-201124569-201175771.exe	89
PID 2300 wrote to memory of 2888	2300	RFQNr.201124559-201124569-201175771.exe	89
PID 2300 wrote to memory of 2888	2300	RFQNr.201124559-201124569-201175771.exe	89
PID 2300 wrote to memory of 2888	2300	RFQNr.201124559-201124569-201175771.exe	89
PID 2300 wrote to memory of 2888	2300	RFQNr.201124559-201124569-201175771.exe	89

C:\Users\Admin\AppData\Local\Temp\RFQNr.201124559-201124569-201175771.exe
"C:\Users\Admin\AppData\Local\Temp\RFQNr.201124559-201124569-201175771.exe"
1⤵
- Loads dropped DLL
- Drops file in System32 directory
- Suspicious use of NtSetInformationThreadHideFromDebugger
- Suspicious use of SetThreadContext
- System Location Discovery: System Language Discovery
- Suspicious behavior: MapViewOfSection
- Suspicious use of WriteProcessMemory
PID:2300
- C:\Users\Admin\AppData\Local\Temp\RFQNr.201124559-201124569-201175771.exe
  "C:\Users\Admin\AppData\Local\Temp\RFQNr.201124559-201124569-201175771.exe"
  2⤵
  - Suspicious use of NtCreateThreadExHideFromDebugger
  - Suspicious use of NtSetInformationThreadHideFromDebugger
  - System Location Discovery: System Language Discovery
  PID:2888

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Persistence

Privilege Escalation

Defense Evasion

Credential Access

Discovery

System Information Discovery

1

T1082

System Location Discovery

1

T1614

System Language Discovery

1

T1614.001

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Replay Monitor

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Downloads

C:\Users\Admin\AppData\Local\Temp\nslAF8A.tmp\System.dll

Filesize
12KB

MD5
8cf2ac271d7679b1d68eefc1ae0c5618

SHA1
7cc1caaa747ee16dc894a600a4256f64fa65a9b8

SHA256
6950991102462d84fdc0e3b0ae30c95af8c192f77ce3d78e8d54e6b22f7c09ba

SHA512
ce828fb9ecd7655cc4c974f78f209d3326ba71ced60171a45a437fc3fff3bd0d69a0997adaca29265c7b5419bdea2b17f8cc8ceae1b8ce6b22b7ed9120bb5ad3

Download Submit
memory/2300-12-0x0000000002A40000-0x0000000004CF2000-memory.dmp

Filesize
34.7MB

Download
memory/2300-13-0x0000000077121000-0x0000000077241000-memory.dmp

Filesize
1.1MB

Download
memory/2300-15-0x00000000745C5000-0x00000000745C6000-memory.dmp

Filesize
4KB

Download
memory/2300-14-0x0000000002A40000-0x0000000004CF2000-memory.dmp

Filesize
34.7MB

Download
memory/2300-16-0x0000000002A40000-0x0000000004CF2000-memory.dmp

Filesize
34.7MB

Download
memory/2888-17-0x00000000016F0000-0x00000000039A2000-memory.dmp

Filesize
34.7MB

Download
memory/2888-18-0x0000000000490000-0x00000000016E4000-memory.dmp

Filesize
18.3MB

Download
memory/2888-23-0x0000000000490000-0x00000000016E4000-memory.dmp

Filesize
18.3MB

Download
memory/2888-24-0x00000000016F0000-0x00000000039A2000-memory.dmp

Filesize
34.7MB

Download
memory/2888-25-0x0000000000490000-0x00000000016E4000-memory.dmp

Filesize
18.3MB

Download
memory/2888-26-0x0000000000490000-0x00000000016E4000-memory.dmp

Filesize
18.3MB

Download
memory/2888-27-0x0000000000490000-0x00000000016E4000-memory.dmp

Filesize
18.3MB

Download
memory/2888-31-0x0000000000490000-0x00000000016E4000-memory.dmp

Filesize
18.3MB

Download
memory/2888-32-0x0000000000490000-0x00000000016E4000-memory.dmp

Filesize
18.3MB

Download
memory/2888-33-0x0000000000490000-0x00000000016E4000-memory.dmp

Filesize
18.3MB

Download
memory/2888-34-0x0000000000490000-0x00000000016E4000-memory.dmp

Filesize
18.3MB

Download
memory/2888-35-0x0000000000490000-0x00000000016E4000-memory.dmp

Filesize
18.3MB

Download
memory/2888-36-0x0000000000490000-0x00000000016E4000-memory.dmp

Filesize
18.3MB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads