asyncrat | c284436ac848ee2ff093e35b1b1a3b75e137adff13c2d3cb070192cd3851bfcd

General

Target

bo.exe
Size

19.4MB
MD5

d11df1a50d4bd2946f22579a59c42533
SHA1

642658e79c5efcfdf1ece6b24f677868e2e5242b
SHA256

c284436ac848ee2ff093e35b1b1a3b75e137adff13c2d3cb070192cd3851bfcd
SHA512

0dbe240d77a2e51198e942f0b48dc92f2d3c40f7eac98f957ede80f5809d4efff24a62f7f10e826b70b1459842391a880c39ab651b53809d4a0451778a04fb66
SSDEEP

393216:V7HMp6xoUGEbCqiYXygxbisWLvhVARbpQgz+exD9ydNwbOVJs:VzMUWUxCD2nZi9vhVAx1+UDAvwbOw

Score

10^/10

asyncrat remcos default test discovery evasion persistence rat themida trojan

Malware Config

Extracted

Family

remcos

Botnet

test

C2

185.25.205.221:2404

Attributes

audio_folder
MicRecords
audio_path
ApplicationPath
audio_record_time
5
connect_delay
0
connect_interval
1
copy_file
font.exe
copy_folder
9910
delete_file
false
hide_file
true
hide_keylog_file
true
install_flag
true
install_path
%WinDir%\System32
keylog_crypt
true
keylog_file
logs.dat
keylog_flag
false
keylog_folder
remcos
mouse_option
false
mutex
Rmc-XVWSQS
screenshot_crypt
false
screenshot_flag
false
screenshot_folder
Screenshots
screenshot_path
%AppData%
screenshot_time
10
take_screenshot_option
false
take_screenshot_time
5

Extracted

Family

asyncrat

Version

1.0.7

Botnet

Default

C2

31.57.135.113:4199

Mutex

w5g64wefd5w4ef

Attributes

delay
1
install
true
install_file
dllhost.exe
install_folder
%AppData%

aes.plain

Signatures

AsyncRat
AsyncRAT is designed to remotely monitor and control other computers written in C#.
rat asyncrat
Asyncrat family
asyncrat
Remcos
Remcos is a closed-source remote control and surveillance software.
rat remcos
Remcos family
remcos

Async RAT payload 1 IoCs

rat

Processes:

resource	yara_rule
C:\Users\Admin\AppData\Roaming\skuld.exe	family_asyncrat

Identifies VirtualBox via ACPI registry values (likely anti-VM) 2 TTPs 1 IoCs
evasion

Query Registry
T1012

Virtualization/Sandbox Evasion
T1497

Processes:

bo.exe

description ioc process

Key opened \REGISTRY\MACHINE\HARDWARE\ACPI\DSDT\VBOX__ bo.exe

description	ioc	process
Key opened	\REGISTRY\MACHINE\HARDWARE\ACPI\DSDT\VBOX__	bo.exe

Checks BIOS information in registry 2 TTPs 2 IoCs

BIOS information is often read in order to detect sandboxing environments.

Query Registry

T1012

System Information Discovery

T1082

Processes:

bo.exe

description	ioc	process
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\SystemBiosVersion	bo.exe
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\VideoBiosVersion	bo.exe

Checks computer location settings 2 TTPs 2 IoCs

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

Query Registry

T1012

System Information Discovery

T1082

Processes:

93213.exeskuld.exe

description	ioc	process
Key value queried	\REGISTRY\USER\S-1-5-21-3495501434-311648039-2993076821-1000\Control Panel\International\Geo\Nation	93213.exe
Key value queried	\REGISTRY\USER\S-1-5-21-3495501434-311648039-2993076821-1000\Control Panel\International\Geo\Nation	skuld.exe

Executes dropped EXE 3 IoCs

Processes:

93213.exeskuld.exedllhost.exe

pid process

1032 93213.exe
1836 skuld.exe
1800 dllhost.exe

Themida packer 14 IoCs

Detects Themida, an advanced Windows software protection system.

themida

Processes:

resource	yara_rule
behavioral1/memory/3672-0-0x00007FF747500000-0x00007FF74967A000-memory.dmp	themida
behavioral1/memory/3672-1-0x00007FF747500000-0x00007FF74967A000-memory.dmp	themida
behavioral1/memory/3672-2-0x00007FF747500000-0x00007FF74967A000-memory.dmp	themida
behavioral1/memory/3672-3-0x00007FF747500000-0x00007FF74967A000-memory.dmp	themida
behavioral1/memory/3672-4-0x00007FF747500000-0x00007FF74967A000-memory.dmp	themida
behavioral1/memory/3672-5-0x00007FF747500000-0x00007FF74967A000-memory.dmp	themida
behavioral1/memory/3672-6-0x00007FF747500000-0x00007FF74967A000-memory.dmp	themida
behavioral1/memory/3672-7-0x00007FF747500000-0x00007FF74967A000-memory.dmp	themida
behavioral1/memory/3672-8-0x00007FF747500000-0x00007FF74967A000-memory.dmp	themida
behavioral1/memory/3672-10-0x00007FF747500000-0x00007FF74967A000-memory.dmp	themida
behavioral1/memory/3672-11-0x00007FF747500000-0x00007FF74967A000-memory.dmp	themida
behavioral1/memory/3672-12-0x00007FF747500000-0x00007FF74967A000-memory.dmp	themida
behavioral1/memory/3672-13-0x00007FF747500000-0x00007FF74967A000-memory.dmp	themida
behavioral1/memory/3672-34-0x00007FF747500000-0x00007FF74967A000-memory.dmp	themida

Adds Run key to start application 2 TTPs 2 IoCs

persistence

Registry Run Keys / Startup Folder

T1547.001

Modify Registry

T1112

Processes:

93213.exe

description	ioc	process
Set value (str)	\REGISTRY\USER\S-1-5-21-3495501434-311648039-2993076821-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\Rmc-XVWSQS = "\"C:\\Windows\\System32\\93213.exe\""	93213.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Run\Rmc-XVWSQS = "\"C:\\Windows\\System32\\93213.exe\""	93213.exe

Checks whether UAC is enabled 1 TTPs 1 IoCs
evasion trojan

System Information Discovery
T1082

Processes:

bo.exe

description ioc process

Key value queried \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA bo.exe
Drops file in System32 directory 1 IoCs

Processes:

bo.exe

description ioc process

File created C:\Windows\System32\93213.exe bo.exe
Suspicious use of NtSetInformationThreadHideFromDebugger 1 IoCs

Processes:

bo.exe

pid process

3672 bo.exe
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 1 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:

93213.exe

description ioc process

Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language 93213.exe
Delays execution with timeout.exe 1 IoCs
evasion

Processes:

timeout.exe

pid process

612 timeout.exe
Scheduled Task/Job: Scheduled Task 1 TTPs 1 IoCs
Schtasks is often used by malware for persistence or to perform post-infection execution.
persistence execution

Scheduled Task
T1053.005

Processes:

schtasks.exe

pid process

1932 schtasks.exe

description	ioc	process
Key value queried	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA	bo.exe

description	ioc	process
File created	C:\Windows\System32\93213.exe	bo.exe

pid	process
3672	bo.exe

description	ioc	process
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	93213.exe

pid	process
612	timeout.exe

pid	process
1932	schtasks.exe

Suspicious behavior: EnumeratesProcesses 21 IoCs

Processes:

93213.exeskuld.exe

pid	process
1032	93213.exe
1032	93213.exe
1836	skuld.exe
1836	skuld.exe
1836	skuld.exe
1836	skuld.exe
1836	skuld.exe
1836	skuld.exe
1836	skuld.exe
1836	skuld.exe
1836	skuld.exe
1836	skuld.exe
1836	skuld.exe
1836	skuld.exe
1836	skuld.exe
1836	skuld.exe
1836	skuld.exe
1836	skuld.exe
1836	skuld.exe
1836	skuld.exe
1836	skuld.exe

Suspicious use of AdjustPrivilegeToken 1 IoCs

Processes:

skuld.exe

description pid process

Token: SeDebugPrivilege 1836 skuld.exe
Suspicious use of SetWindowsHookEx 1 IoCs

Processes:

93213.exe

pid process

1032 93213.exe

description	pid	process
Token: SeDebugPrivilege	1836	skuld.exe

Suspicious use of WriteProcessMemory 15 IoCs

Processes:

bo.exe93213.exeskuld.execmd.execmd.exe

description	pid	process	target process
PID 3672 wrote to memory of 1032	3672	bo.exe	93213.exe
PID 3672 wrote to memory of 1032	3672	bo.exe	93213.exe
PID 3672 wrote to memory of 1032	3672	bo.exe	93213.exe
PID 1032 wrote to memory of 1836	1032	93213.exe	skuld.exe
PID 1032 wrote to memory of 1836	1032	93213.exe	skuld.exe
PID 1836 wrote to memory of 4040	1836	skuld.exe	cmd.exe
PID 1836 wrote to memory of 4040	1836	skuld.exe	cmd.exe
PID 1836 wrote to memory of 1992	1836	skuld.exe	cmd.exe
PID 1836 wrote to memory of 1992	1836	skuld.exe	cmd.exe
PID 1992 wrote to memory of 612	1992	cmd.exe	timeout.exe
PID 1992 wrote to memory of 612	1992	cmd.exe	timeout.exe
PID 4040 wrote to memory of 1932	4040	cmd.exe	schtasks.exe
PID 4040 wrote to memory of 1932	4040	cmd.exe	schtasks.exe
PID 1992 wrote to memory of 1800	1992	cmd.exe	dllhost.exe
PID 1992 wrote to memory of 1800	1992	cmd.exe	dllhost.exe

Uses Task Scheduler COM API 1 TTPs
The Task Scheduler COM API can be used to schedule applications to run on boot or at set times.
persistence

Query Registry
T1012

C:\Users\Admin\AppData\Local\Temp\bo.exe
"C:\Users\Admin\AppData\Local\Temp\bo.exe"
1⤵
- Identifies VirtualBox via ACPI registry values (likely anti-VM)
- Checks BIOS information in registry
- Checks whether UAC is enabled
- Drops file in System32 directory
- Suspicious use of NtSetInformationThreadHideFromDebugger
- Suspicious use of WriteProcessMemory
PID:3672
- C:\Windows\System32\93213.exe
  "C:\Windows\System32\93213.exe"
  2⤵
  - Checks computer location settings
  - Executes dropped EXE
  - Adds Run key to start application
  - System Location Discovery: System Language Discovery
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of SetWindowsHookEx
  - Suspicious use of WriteProcessMemory
  PID:1032
- - C:\Users\Admin\AppData\Roaming\skuld.exe
    "C:\Users\Admin\AppData\Roaming\skuld.exe"
    3⤵
    - Checks computer location settings
    - Executes dropped EXE
    - Suspicious behavior: EnumeratesProcesses
    - Suspicious use of AdjustPrivilegeToken
    - Suspicious use of WriteProcessMemory
    PID:1836
  - - C:\Windows\System32\cmd.exe
      "C:\Windows\System32\cmd.exe" /c schtasks /create /f /sc onlogon /rl highest /tn "dllhost" /tr '"C:\Users\Admin\AppData\Roaming\dllhost.exe"' & exit
      4⤵
      Suspicious use of WriteProcessMemory
      PID:4040
    - - C:\Windows\system32\schtasks.exe
        
        schtasks /create /f /sc onlogon /rl highest /tn "dllhost" /tr '"C:\Users\Admin\AppData\Roaming\dllhost.exe"'
        5⤵
        Scheduled Task/Job: Scheduled Task
        
        PID:1932
  - - C:\Windows\system32\cmd.exe
      C:\Windows\system32\cmd.exe /c ""C:\Users\Admin\AppData\Local\Temp\tmp1AB7.tmp.bat""
      4⤵
      Suspicious use of WriteProcessMemory
      PID:1992
    - - C:\Windows\system32\timeout.exe
        
        timeout 3
        5⤵
        Delays execution with timeout.exe
        
        PID:612
    - - C:\Users\Admin\AppData\Roaming\dllhost.exe
        
        "C:\Users\Admin\AppData\Roaming\dllhost.exe"
        5⤵
        Executes dropped EXE
        
        PID:1800

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Persistence

Boot or Logon Autostart Execution

1

T1547

Registry Run Keys / Startup Folder

1

T1547.001

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Privilege Escalation

Boot or Logon Autostart Execution

1

T1547

Registry Run Keys / Startup Folder

1

T1547.001

Scheduled Task/Job

1

T1053

Scheduled Task

1

T1053.005

Defense Evasion

Modify Registry

1

T1112

Virtualization/Sandbox Evasion

1

T1497

Credential Access

Discovery

Query Registry

4

T1012

System Information Discovery

4

T1082

System Location Discovery

1

T1614

System Language Discovery

1

T1614.001

Virtualization/Sandbox Evasion

1

T1497

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

C:\Users\Admin\AppData\Local\Temp\tmp1AB7.tmp.bat

Filesize
151B

MD5
e4541af8ef2a04fdb74838c200ee044a

SHA1
c2e06cc669b1b776695ec61b071ce8ff2f0857f8

SHA256
ff926b1a8178c5d7dcce0ca900946cc25dfda825abe300812b5d0f28e5e22ec0

SHA512
d57605de36c9113c7f2bdaf9570a63bbab9cf83b6ad0b6dd20f65f04a55b202d16c5be60989363347b157b39f1adbcbd0606f4a5d759882ced354882659e3986

Download Submit
C:\Users\Admin\AppData\Roaming\skuld.exe

Filesize
63KB

MD5
6c7adc2f28f40d79c09fdd2d59a94ab0

SHA1
48c3f3223376146c61a00c948447c188147c5dae

SHA256
109c3b63306fcc197268155a8f45681e14987eb207d4b8eef74978cf5a4114e6

SHA512
d3db6d8ec0835540299c0faf35d87327090d36b6fa3fd14fc26a452bdb7c084093d2424238ee0e2b847d07c33cb871f7cf5cd428226b08e1fc317ed88259a4a6

Download Submit
C:\Windows\System32\93213.exe

Filesize
481KB

MD5
5cd8c409f784d3ed2ddaaeefec65088a

SHA1
acc55ffb98055b6f30177f7bfa337ee2bf99f45b

SHA256
924cc96243a3cc5c928c4acfde01a5b468e943f67c36c292bc08c6c8e57c82be

SHA512
8c935da4e7a6c59401c3efbcdad122eb8ac9dca5b39ca8d114182c7e53cf7008ec4188d69865609dd7a90f055ac60c68a1597c673c8953d1601a5d7c648327d6

Download Submit
memory/1836-33-0x0000000000B60000-0x0000000000B76000-memory.dmp

Filesize
88KB

Download
memory/3672-9-0x00007FFD312D1000-0x00007FFD312D3000-memory.dmp

Filesize
8KB

Download
memory/3672-11-0x00007FF747500000-0x00007FF74967A000-memory.dmp

Filesize
33.5MB

Download
memory/3672-6-0x00007FF747500000-0x00007FF74967A000-memory.dmp

Filesize
33.5MB

Download
memory/3672-7-0x00007FF747500000-0x00007FF74967A000-memory.dmp

Filesize
33.5MB

Download
memory/3672-0-0x00007FF747500000-0x00007FF74967A000-memory.dmp

Filesize
33.5MB

Download
memory/3672-8-0x00007FF747500000-0x00007FF74967A000-memory.dmp

Filesize
33.5MB

Download
memory/3672-10-0x00007FF747500000-0x00007FF74967A000-memory.dmp

Filesize
33.5MB

Download
memory/3672-5-0x00007FF747500000-0x00007FF74967A000-memory.dmp

Filesize
33.5MB

Download
memory/3672-12-0x00007FF747500000-0x00007FF74967A000-memory.dmp

Filesize
33.5MB

Download
memory/3672-13-0x00007FF747500000-0x00007FF74967A000-memory.dmp

Filesize
33.5MB

Download
memory/3672-4-0x00007FF747500000-0x00007FF74967A000-memory.dmp

Filesize
33.5MB

Download
memory/3672-3-0x00007FF747500000-0x00007FF74967A000-memory.dmp

Filesize
33.5MB

Download
memory/3672-2-0x00007FF747500000-0x00007FF74967A000-memory.dmp

Filesize
33.5MB

Download
memory/3672-34-0x00007FF747500000-0x00007FF74967A000-memory.dmp

Filesize
33.5MB

Download
memory/3672-1-0x00007FF747500000-0x00007FF74967A000-memory.dmp

Filesize
33.5MB

Download

Resubmissions

Analysis

Sharing

General

Malware Config

Extracted

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v15

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Downloads