Analysis
-
max time kernel
103s -
max time network
135s -
platform
windows10-2004_x64 -
resource
win10v2004-20250314-en -
resource tags
arch:x64arch:x86image:win10v2004-20250314-enlocale:en-usos:windows10-2004-x64system -
submitted
04/04/2025, 22:06
Behavioral task
behavioral1
Sample
Catto.exe
Resource
win10v2004-20250314-en
General
-
Target
Catto.exe
-
Size
343KB
-
MD5
8ed3ba6941919a0d9bb1cb5007476949
-
SHA1
95d3a559bb1842ec2b4c6f9d58ef0273f72740ff
-
SHA256
11e508b38307c2ee091406449b78fc1e5cae7d48ac40e4fc3339cb31a4d52754
-
SHA512
b1ad1f260c12f6642b54c787d05bf34456dcd7839f3b533583769b694adfe07006524511a2a09018f5c39e1fada17a373614837af2db5f3931eb7b3147e69f47
-
SSDEEP
3072:wCc9Km9m2n1ycrCcjtTzqP/Jf7R/9lmyAnMyYVO3zlN5xu2ZsRYHeQKkMjnXJ+Zi:Lc9picmax+JAn7Q8zlA+H+QxonXS
Malware Config
Signatures
-
Chaos
Ransomware family first seen in June 2021.
-
Chaos Ransomware 2 IoCs
resource yara_rule behavioral1/memory/3456-1-0x0000000000B80000-0x0000000000BDC000-memory.dmp family_chaos behavioral1/files/0x000f000000024061-6.dat family_chaos -
Chaos family
-
Renames multiple (195) files with added filename extension
This suggests ransomware activity of encrypting all the files on the system.
-
Checks computer location settings 2 TTPs 2 IoCs
Looks up country code configured in the registry, likely geofence.
description ioc Process Key value queried \REGISTRY\USER\S-1-5-21-1062200478-553497403-3857448183-1000\Control Panel\International\Geo\Nation Catto.exe Key value queried \REGISTRY\USER\S-1-5-21-1062200478-553497403-3857448183-1000\Control Panel\International\Geo\Nation svchost.exe -
Drops startup file 3 IoCs
description ioc Process File created C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\svchost.url svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\desktop.ini svchost.exe File created C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\README.txt svchost.exe -
Executes dropped EXE 1 IoCs
pid Process 4276 svchost.exe -
Reads user/profile data of web browsers 3 TTPs
Infostealers often target stored browser data, which can include saved credentials etc.
-
Drops desktop.ini file(s) 64 IoCs
description ioc Process File opened for modification C:\Users\Admin\Favorites\Links\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Pictures\desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\Accessibility\desktop.ini svchost.exe File opened for modification C:\Users\Public\Pictures\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Windows\Burn\Burn\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\System Tools\Desktop.ini svchost.exe File opened for modification C:\Users\Admin\Pictures\Camera Roll\desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\System Tools\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Windows\Burn\Burn2\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Windows\History\desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\Maintenance\Desktop.ini svchost.exe File opened for modification C:\Users\Default\AppData\Local\Microsoft\Windows\WinX\Group2\desktop.ini svchost.exe File opened for modification C:\Users\Default\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Accessibility\desktop.ini svchost.exe File opened for modification C:\Users\Public\desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\Accessories\System Tools\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Internet Explorer\Quick Launch\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Internet Explorer\Quick Launch\User Pinned\TaskBar\desktop.ini svchost.exe File opened for modification C:\Users\Public\Documents\desktop.ini svchost.exe File opened for modification C:\Users\Public\Downloads\desktop.ini svchost.exe File opened for modification F:\$RECYCLE.BIN\S-1-5-21-1062200478-553497403-3857448183-1000\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\SendTo\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Contacts\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Downloads\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Music\desktop.ini svchost.exe File opened for modification C:\Users\Public\Desktop\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Recent\desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\Accessories\desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\Windows PowerShell\desktop.ini svchost.exe File opened for modification C:\Users\Public\Music\desktop.ini svchost.exe File opened for modification C:\Users\Public\Videos\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Windows\Burn\Burn1\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Favorites\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Searches\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Videos\desktop.ini svchost.exe File opened for modification C:\Users\Default\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Accessories\desktop.ini svchost.exe File opened for modification C:\Users\Public\Libraries\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Documents\desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\desktop.ini svchost.exe File opened for modification C:\Users\Public\AccountPictures\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\AccountPictures\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Administrative Tools\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Saved Games\desktop.ini svchost.exe File opened for modification C:\Users\Default\AppData\Local\Microsoft\Windows\WinX\Group3\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Windows\WinX\Group1\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Windows\WinX\Group2\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Windows\WinX\Group3\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Libraries\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Accessibility\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Accessories\desktop.ini svchost.exe File opened for modification C:\Users\Admin\OneDrive\desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\Administrative Tools\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Links\desktop.ini svchost.exe File opened for modification C:\Users\Default\AppData\Roaming\Microsoft\Internet Explorer\Quick Launch\desktop.ini svchost.exe File opened for modification C:\Users\Default\AppData\Roaming\Microsoft\Windows\SendTo\desktop.ini svchost.exe File opened for modification C:\Users\Default\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Maintenance\Desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\StartUp\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Desktop\desktop.ini svchost.exe File opened for modification C:\Users\Admin\3D Objects\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Maintenance\Desktop.ini svchost.exe File opened for modification C:\Users\Admin\Pictures\Saved Pictures\desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\desktop.ini svchost.exe File opened for modification C:\Users\Default\AppData\Local\Microsoft\Windows\WinX\Group1\desktop.ini svchost.exe -
Sets desktop wallpaper using registry 2 TTPs 1 IoCs
description ioc Process Set value (str) \REGISTRY\USER\S-1-5-21-1062200478-553497403-3857448183-1000\Control Panel\Desktop\Wallpaper = "C:\\Users\\Admin\\AppData\\Local\\Temp\\s1sishw90.jpg" svchost.exe -
Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s).
-
Modifies registry class 1 IoCs
description ioc Process Key created \REGISTRY\USER\S-1-5-21-1062200478-553497403-3857448183-1000_Classes\Local Settings svchost.exe -
Opens file in notepad (likely ransom note) 1 IoCs
pid Process 4932 NOTEPAD.EXE -
Suspicious behavior: AddClipboardFormatListener 1 IoCs
pid Process 4276 svchost.exe -
Suspicious behavior: EnumeratesProcesses 47 IoCs
pid Process 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 3456 Catto.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe 4276 svchost.exe -
Suspicious use of AdjustPrivilegeToken 2 IoCs
description pid Process Token: SeDebugPrivilege 3456 Catto.exe Token: SeDebugPrivilege 4276 svchost.exe -
Suspicious use of WriteProcessMemory 4 IoCs
description pid Process procid_target PID 3456 wrote to memory of 4276 3456 Catto.exe 92 PID 3456 wrote to memory of 4276 3456 Catto.exe 92 PID 4276 wrote to memory of 4932 4276 svchost.exe 96 PID 4276 wrote to memory of 4932 4276 svchost.exe 96
Processes
-
C:\Users\Admin\AppData\Local\Temp\Catto.exe"C:\Users\Admin\AppData\Local\Temp\Catto.exe"1⤵
- Checks computer location settings
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:3456 -
C:\Users\Admin\AppData\Roaming\svchost.exe"C:\Users\Admin\AppData\Roaming\svchost.exe"2⤵
- Checks computer location settings
- Drops startup file
- Executes dropped EXE
- Drops desktop.ini file(s)
- Sets desktop wallpaper using registry
- Modifies registry class
- Suspicious behavior: AddClipboardFormatListener
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:4276 -
C:\Windows\system32\NOTEPAD.EXE"C:\Windows\system32\NOTEPAD.EXE" C:\Users\Admin\AppData\Roaming\README.txt3⤵
- Opens file in notepad (likely ransom note)
PID:4932
-
-
Network
MITRE ATT&CK Enterprise v15
Replay Monitor
Loading Replay Monitor...
Downloads
-
Filesize
1B
MD5d1457b72c3fb323a2671125aef3eab5d
SHA15bab61eb53176449e25c2c82f172b82cb13ffb9d
SHA2568a8de823d5ed3e12746a62ef169bcf372be0ca44f0a1236abc35df05d96928e1
SHA512ca63c07ad35d8c9fb0c92d6146759b122d4ec5d3f67ebe2f30ddb69f9e6c9fd3bf31a5e408b08f1d4d9cd68120cced9e57f010bef3cde97653fed5470da7d1a0
-
Filesize
226B
MD528d7fcc2b910da5e67ebb99451a5f598
SHA1a5bf77a53eda1208f4f37d09d82da0b9915a6747
SHA2562391511d0a66ed9f84ae54254f51c09e43be01ad685db80da3201ec880abd49c
SHA5122d8eb65cbf04ca506f4ef3b9ae13ccf05ebefab702269ba70ffd1ce9e6c615db0a3ee3ac0e81a06f546fc3250b7b76155dd51241c41b507a441b658c8e761df6
-
Filesize
343KB
MD58ed3ba6941919a0d9bb1cb5007476949
SHA195d3a559bb1842ec2b4c6f9d58ef0273f72740ff
SHA25611e508b38307c2ee091406449b78fc1e5cae7d48ac40e4fc3339cb31a4d52754
SHA512b1ad1f260c12f6642b54c787d05bf34456dcd7839f3b533583769b694adfe07006524511a2a09018f5c39e1fada17a373614837af2db5f3931eb7b3147e69f47
-
Filesize
1KB
MD5d8db68b8cc14c9c746f86e44055897c6
SHA1b34628fb98380a92c1cec38f4dc3196bbc1d4f3a
SHA256f7820212cb8da8c900d1ed61ab600ae54513a77a787a5016aacf559996a583a1
SHA5129d4b0e159865449f1c5ec923f5db828ec3c0e1c2b205af325fee77db850c6d85fac4b528fa4704bec35ca75ff6d16a57b1dc3946c53e108b7c127db2205a0c59