Malware Analysis Report

2024-08-06 09:26

Sample ID 230731-nvq1eseh69
Target yOMHr.exe
SHA256 8b0a5fb13309623c3518473551cb1f55d38d8450129d4a3c16b476f7b2867d7d
Tags
ryuk persistence ransomware
score
10/10

Table of Contents

Analysis Overview

MITRE ATT&CK Matrix

Analysis: static1

Detonation Overview

Signatures

Analysis: behavioral1

Detonation Overview

Command Line

Signatures

Processes

Network

Files

Analysis: behavioral2

Detonation Overview

Command Line

Signatures

Processes

Network

Files

Analysis Overview

score
10/10

SHA256

8b0a5fb13309623c3518473551cb1f55d38d8450129d4a3c16b476f7b2867d7d

Threat Level: Known bad

The file yOMHr.exe was found to be: Known bad.

Malicious Activity Summary

ryuk persistence ransomware

Ryuk

Checks computer location settings

Adds Run key to start application

Drops file in Program Files directory

Unsigned PE

Enumerates physical storage devices

Suspicious use of WriteProcessMemory

Suspicious behavior: EnumeratesProcesses

Suspicious use of AdjustPrivilegeToken

MITRE ATT&CK Matrix V13

Analysis: static1

Detonation Overview

Reported

2023-07-31 11:43

Signatures

Unsigned PE

Description Indicator Process Target
N/A N/A N/A N/A

Analysis: behavioral1

Detonation Overview

Submitted

2023-07-31 11:43

Reported

2023-07-31 11:44

Platform

win7-20230712-en

Max time kernel

68s

Max time network

18s

Command Line

"taskhost.exe"

Signatures

Ryuk

ransomware ryuk

Adds Run key to start application

persistence
Description Indicator Process Target
Key created \REGISTRY\USER\S-1-5-21-1014134971-2480516131-292343513-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run C:\Windows\system32\reg.exe N/A
Set value (str) \REGISTRY\USER\S-1-5-21-1014134971-2480516131-292343513-1000\Software\Microsoft\Windows\CurrentVersion\Run\svchos = "C:\\Users\\Admin\\AppData\\Local\\Temp\\yOMHr.exe" C:\Windows\system32\reg.exe N/A

Drops file in Program Files directory

Description Indicator Process Target
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\Sports\GoldRing.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\Microsoft Shared\ink\fsdefinitions\osknumpad\RyukReadMe.txt C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\System\ado\msadox28.tlb C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\Performance\ParentMenuButtonIconSubpict.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\Pets\Pets_image-frame-ImageMask.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\SpecialOccasion\NavigationLeft_SelectionSubpicture.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\SpecialOccasion\whitemask1047.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\RyukReadMe.txt C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\Microsoft Shared\ink\hwresslm.dat C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\Microsoft Shared\ink\nl-NL\RyukReadMe.txt C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\Performance\userContent_16x9_imagemask.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\Pets\Scenes_LOOP_BG.wmv C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\Pets\Pets_frame-shadow.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\SpecialOccasion\SpecialNavigationRight_SelectionSubpicture.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\Sports\SportsNotesBackground_PAL.wmv C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\7-Zip\7zCon.sfx C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\7-Zip\History.txt C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\System\Ole DB\en-US\RyukReadMe.txt C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\BabyBoy\BabyBoyMainBackground_PAL.wmv C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\Performance\Title_Trans_Scene_PAL.wmv C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\Push\NavigationUp_ButtonGraphic.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\rectangle_travel_Thumbnail.bmp C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\SpecialOccasion\SpecialNavigationLeft_SelectionSubpicture.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\7-Zip\Lang\nl.txt C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\Microsoft Shared\ink\fsdefinitions\symbols\symbase.xml C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\Microsoft Shared\Stationery\RyukReadMe.txt C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\bod_r.TTF C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\16to9Squareframe_VideoInset.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\Microsoft Shared\Stationery\Roses.jpg C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\4to3Squareframe_SelectionSubpicture.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\LayeredTitles\NavigationRight_SelectionSubpicture.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\Full\NavigationUp_ButtonGraphic.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\Pets\Pets_btn-back-over-select.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\Microsoft Shared\ink\HWRCustomization\RyukReadMe.txt C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\Microsoft Shared\ink\ipskor.xml C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\Microsoft Shared\VSTO\10.0\VSTOInstaller.config C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\System\msadc\handsafe.reg C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\RyukReadMe.txt C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\SpecialOccasion\NavigationLeft_ButtonGraphic.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\Microsoft Shared\ink\hwresmlm.dat C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\Microsoft Shared\OfficeSoftwareProtectionPlatform\osppobjs-spp-plugin-manifest-signed.xrm-ms C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\System\Ole DB\oledbjvs.inc C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\Performance\Notes_loop_PAL.wmv C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\Postage_VideoInset.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\Microsoft Shared\Stationery\Soft Blue.htm C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\Microsoft Shared\Stationery\SoftBlue.jpg C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\rtstreamsink.ax C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\BabyGirl\chapters-static.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\Rectangles\NavigationRight_SelectionSubpicture.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\System\Ole DB\fr-FR\RyukReadMe.txt C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\Pets\Pets_btn-previous-over-select.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\Shatter\203x8subpicture.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\Microsoft Shared\ink\fsdefinitions\main.xml C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\Microsoft Shared\ink\hwrcommonlm.dat C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\Microsoft Shared\ink\ipsrus.xml C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\NavigationUp_SelectionSubpicture.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\shadowonlyframe_buttongraphic.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\7-Zip\Lang\br.txt C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\Microsoft Shared\ink\fsdefinitions\symbols.xml C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\Common Files\SpeechEngines\Microsoft\TTS20\en-US\RyukReadMe.txt C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\BlackRectangle.bmp C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\offset.ax C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\FlipPage\NavigationUp_SelectionSubpicture.png C:\Windows\system32\taskhost.exe N/A
File opened for modification C:\Program Files\DVD Maker\Shared\DvdStyles\rectangle_performance_Thumbnail.bmp C:\Windows\system32\taskhost.exe N/A

Enumerates physical storage devices

Suspicious behavior: EnumeratesProcesses

Description Indicator Process Target
N/A N/A C:\Users\Admin\AppData\Local\Temp\yOMHr.exe N/A

Suspicious use of AdjustPrivilegeToken

Description Indicator Process Target
Token: SeDebugPrivilege N/A C:\Users\Admin\AppData\Local\Temp\yOMHr.exe N/A

Processes

C:\Windows\system32\taskhost.exe

"taskhost.exe"

C:\Windows\system32\Dwm.exe

"C:\Windows\system32\Dwm.exe"

C:\Users\Admin\AppData\Local\Temp\yOMHr.exe

"C:\Users\Admin\AppData\Local\Temp\yOMHr.exe"

C:\Windows\System32\cmd.exe

"C:\Windows\System32\cmd.exe" /C REG ADD "HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" /v "svchos" /t REG_SZ /d "C:\Users\Admin\AppData\Local\Temp\yOMHr.exe" /f

C:\Windows\system32\reg.exe

REG ADD "HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" /v "svchos" /t REG_SZ /d "C:\Users\Admin\AppData\Local\Temp\yOMHr.exe" /f

Network

N/A

Files

memory/1116-53-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-55-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-56-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

C:\RyukReadMe.txt

MD5 cd99cba6153cbc0b14b7a849e4d0180f
SHA1 375961866404a705916cbc6cd4915de7d9778923
SHA256 74c43a177917b1d57ea2eaf6212ccf3b9012b4d68bc45284349443eed0bf5ee2
SHA512 0c9f250c0e2ec9736b072a9807b6c3bec4b670ab2f511e65cf5d79e9a8c9a209eb91736ce2765b52b6d94a57c6aa1c16bb08e16727660699b70608439c8b7cda

memory/1116-70-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-73-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-71-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-77-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-76-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-79-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-82-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-88-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-84-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-86-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-92-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-95-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-98-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-99-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-104-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-107-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-110-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-113-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-117-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-127-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-134-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-130-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-129-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-126-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-123-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-120-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-115-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1160-137-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-141-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-142-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-143-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-145-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-148-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-151-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-154-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-155-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-156-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-161-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-158-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-169-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

memory/1116-167-0x000000013F9E0000-0x000000013FD6E000-memory.dmp

Analysis: behavioral2

Detonation Overview

Submitted

2023-07-31 11:43

Reported

2023-07-31 11:46

Platform

win10v2004-20230703-en

Max time kernel

7s

Max time network

72s

Command Line

C:\Windows\system32\svchost.exe -k ClipboardSvcGroup -p -s cbdhsvc

Signatures

Checks computer location settings

Description Indicator Process Target
Key value queried \REGISTRY\USER\S-1-5-21-1420546310-613437930-2990200354-1000\Control Panel\International\Geo\Nation C:\Users\Admin\AppData\Local\Temp\yOMHr.exe N/A

Adds Run key to start application

persistence
Description Indicator Process Target
Key created \REGISTRY\USER\S-1-5-21-1420546310-613437930-2990200354-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run C:\Windows\system32\reg.exe N/A
Set value (str) \REGISTRY\USER\S-1-5-21-1420546310-613437930-2990200354-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\svchos = "C:\\Users\\Admin\\AppData\\Local\\Temp\\yOMHr.exe" C:\Windows\system32\reg.exe N/A

Enumerates physical storage devices

Suspicious behavior: EnumeratesProcesses

Description Indicator Process Target
N/A N/A C:\Users\Admin\AppData\Local\Temp\yOMHr.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\yOMHr.exe N/A

Suspicious use of AdjustPrivilegeToken

Description Indicator Process Target
Token: SeDebugPrivilege N/A C:\Users\Admin\AppData\Local\Temp\yOMHr.exe N/A

Processes

C:\Windows\system32\svchost.exe

C:\Windows\system32\svchost.exe -k ClipboardSvcGroup -p -s cbdhsvc

C:\Windows\system32\taskhostw.exe

taskhostw.exe {222A245B-E637-4AE9-A93F-A59CA119A75E}

C:\Windows\system32\svchost.exe

C:\Windows\system32\svchost.exe -k UnistackSvcGroup -s CDPUserSvc

C:\Windows\system32\sihost.exe

sihost.exe

C:\Users\Admin\AppData\Local\Temp\yOMHr.exe

"C:\Users\Admin\AppData\Local\Temp\yOMHr.exe"

C:\Windows\System32\cmd.exe

"C:\Windows\System32\cmd.exe" /C REG ADD "HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" /v "svchos" /t REG_SZ /d "C:\Users\Admin\AppData\Local\Temp\yOMHr.exe" /f

C:\Windows\system32\reg.exe

REG ADD "HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" /v "svchos" /t REG_SZ /d "C:\Users\Admin\AppData\Local\Temp\yOMHr.exe" /f

Network

Country Destination Domain Proto
US 8.8.8.8:53 208.194.73.20.in-addr.arpa udp
US 8.8.8.8:53 95.221.229.192.in-addr.arpa udp
US 8.8.8.8:53 58.99.105.20.in-addr.arpa udp
US 8.8.8.8:53 161.252.72.23.in-addr.arpa udp

Files

memory/2460-133-0x00007FF7973E0000-0x00007FF79776E000-memory.dmp

memory/2460-134-0x00007FF7973E0000-0x00007FF79776E000-memory.dmp