Analysis
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max time kernel
150s -
max time network
13s -
platform
windows7_x64 -
resource
win7v20210410 -
submitted
26-07-2021 12:57
Static task
static1
Behavioral task
behavioral1
Sample
128a0f0cd5d10f864d5a0741ba25996b2bf74f580ac7918dec6516215801e39a.sample.exe
Resource
win7v20210410
Behavioral task
behavioral2
Sample
128a0f0cd5d10f864d5a0741ba25996b2bf74f580ac7918dec6516215801e39a.sample.exe
Resource
win10v20210410
General
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Target
128a0f0cd5d10f864d5a0741ba25996b2bf74f580ac7918dec6516215801e39a.sample.exe
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Size
1.1MB
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MD5
446e594e266f5e52064fd69a333867f6
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SHA1
5c94d21af50f54472cee2cbdb09ec5c7d3361916
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SHA256
128a0f0cd5d10f864d5a0741ba25996b2bf74f580ac7918dec6516215801e39a
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SHA512
8f389d7f2b7fbf508a23b29ee4d282fbeedaf94cb3de182df8886680bdc752c35fdd0e94b0034ea3dbc440b1a5e87387bea3994241e3e4eb77af091000a57f05
Malware Config
Extracted
C:\Program Files (x86)\Microsoft Office\CLIPART\PUB60COR\!Decrypt-All-Files-yayejrd.txt
http://6ubux6ppafr24izl.onion.cab
http://6ubux6ppafr24izl.tor2web.org
http://6ubux6ppafr24izl.onion/
Extracted
C:\Users\Admin\Documents\!Decrypt-All-Files-yayejrd.txt
http://6ubux6ppafr24izl.onion.cab
http://6ubux6ppafr24izl.tor2web.org
http://6ubux6ppafr24izl.onion/
Extracted
C:\ProgramData\ummcbbc.html
http://6ubux6ppafr24izl.onion.cab
http://6ubux6ppafr24izl.tor2web.org
http://6ubux6ppafr24izl.onion
Signatures
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CTB-Locker
Ransomware family which uses Tor to hide its C2 communications.
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Deletes shadow copies 2 TTPs
Ransomware often targets backup files to inhibit system recovery.
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Executes dropped EXE 2 IoCs
pid Process 1812 exusltb.exe 1544 exusltb.exe -
Modifies extensions of user files 1 IoCs
Ransomware generally changes the extension on encrypted files.
description ioc Process File renamed C:\Windows\Temp\laaaaaaa.tmp => C:\Users\Admin\Pictures\GroupInstall.RAW.yayejrd svchost.exe -
Checks computer location settings 2 TTPs 1 IoCs
Looks up country code configured in the registry, likely geofence.
description ioc Process Key value queried \REGISTRY\USER\S-1-5-21-2513283230-931923277-594887482-1000\Control Panel\International\Geo\Nation exusltb.exe -
Drops desktop.ini file(s) 1 IoCs
description ioc Process File opened for modification C:\$RECYCLE.BIN\S-1-5-18\desktop.ini svchost.exe -
Drops file in System32 directory 1 IoCs
description ioc Process File opened for modification C:\Windows\SysWOW64\config\systemprofile\AppData\Local\Microsoft\Windows\Temporary Internet Files\counters.dat exusltb.exe -
Sets desktop wallpaper using registry 2 TTPs 1 IoCs
description ioc Process Set value (str) \REGISTRY\USER\S-1-5-21-2513283230-931923277-594887482-1000\Control Panel\Desktop\Wallpaper = "C:\\Users\\Admin\\Documents\\!Decrypt-All-Files-yayejrd.bmp" Explorer.EXE -
Drops file in Program Files directory 2 IoCs
description ioc Process File created C:\Program Files (x86)\Microsoft Office\CLIPART\PUB60COR\!Decrypt-All-Files-yayejrd.txt svchost.exe File created C:\Program Files (x86)\Microsoft Office\CLIPART\PUB60COR\!Decrypt-All-Files-yayejrd.bmp svchost.exe -
Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s). Likely ransomware behaviour.
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Interacts with shadow copies 2 TTPs 1 IoCs
Shadow copies are often targeted by ransomware to inhibit system recovery.
pid Process 520 vssadmin.exe -
description ioc Process Key created \REGISTRY\USER\S-1-5-21-2513283230-931923277-594887482-1000\Software\Microsoft\Internet Explorer\Main exusltb.exe Key created \REGISTRY\USER\S-1-5-21-2513283230-931923277-594887482-1000\Software\Microsoft\Internet Explorer\Main\WindowsSearch exusltb.exe Set value (str) \REGISTRY\USER\S-1-5-21-2513283230-931923277-594887482-1000\Software\Microsoft\Internet Explorer\Main\WindowsSearch\Version = "WS not running" exusltb.exe -
Modifies data under HKEY_USERS 19 IoCs
description ioc Process Key created \REGISTRY\USER\.DEFAULT\Software svchost.exe Key created \REGISTRY\USER\.DEFAULT\Software\Microsoft svchost.exe Key created \REGISTRY\USER\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer\CLSID svchost.exe Key created \REGISTRY\USER\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer\CLSID\{645FF040-5081-101B-9F08-00AA002F954E} svchost.exe Set value (str) \REGISTRY\USER\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer\CLSID\{645FF040-5081-101B-9F08-00AA002F954E}\DefaultIcon\Full = "%SystemRoot%\\System32\\imageres.dll,-54" svchost.exe Set value (str) \REGISTRY\USER\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer\CLSID\{645FF040-5081-101B-9F08-00AA002F954E}\DefaultIcon\Empty = "%SystemRoot%\\System32\\imageres.dll,-55" svchost.exe Key created \REGISTRY\USER\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer\BitBucket\Volume svchost.exe Set value (int) \REGISTRY\USER\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer\BitBucket\Volume\{efb60be4-9a04-11eb-be03-806e6f6e6963}\MaxCapacity = "15140" svchost.exe Set value (data) \REGISTRY\USER\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer\BitBucket\LastEnum = 30002c007b00650066006200360030006200650034002d0039006100300034002d0031003100650062002d0062006500300033002d003800300036006500360066003600650036003900360033007d0000000000 svchost.exe Key created \REGISTRY\USER\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer\CLSID\{645FF040-5081-101B-9F08-00AA002F954E}\DefaultIcon svchost.exe Key created \REGISTRY\USER\.DEFAULT\Software\Microsoft\Windows svchost.exe Key created \REGISTRY\USER\.DEFAULT\Software\Microsoft\Windows\CurrentVersion svchost.exe Key created \REGISTRY\USER\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer\BitBucket svchost.exe Set value (int) \REGISTRY\USER\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer\BitBucket\Volume\{efb60be4-9a04-11eb-be03-806e6f6e6963}\NukeOnDelete = "0" svchost.exe Set value (str) \REGISTRY\USER\.DEFAULT\Control Panel\Desktop\TileWallpaper = "0" svchost.exe Set value (str) \REGISTRY\USER\.DEFAULT\Control Panel\Desktop\WallpaperStyle = "0" svchost.exe Key created \REGISTRY\USER\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer\BitBucket\Volume\{efb60be4-9a04-11eb-be03-806e6f6e6963} svchost.exe Key created \REGISTRY\USER\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer svchost.exe Set value (str) \REGISTRY\USER\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer\CLSID\{645FF040-5081-101B-9F08-00AA002F954E}\DefaultIcon\ = "%SystemRoot%\\System32\\imageres.dll,-55" svchost.exe -
Suspicious behavior: EnumeratesProcesses 6 IoCs
pid Process 788 128a0f0cd5d10f864d5a0741ba25996b2bf74f580ac7918dec6516215801e39a.sample.exe 1812 exusltb.exe 1812 exusltb.exe 1812 exusltb.exe 1812 exusltb.exe 1812 exusltb.exe -
Suspicious behavior: GetForegroundWindowSpam 1 IoCs
pid Process 1256 Explorer.EXE -
Suspicious use of AdjustPrivilegeToken 3 IoCs
description pid Process Token: SeDebugPrivilege 1812 exusltb.exe Token: SeDebugPrivilege 1812 exusltb.exe Token: SeShutdownPrivilege 1256 Explorer.EXE -
Suspicious use of FindShellTrayWindow 5 IoCs
pid Process 1544 exusltb.exe 1256 Explorer.EXE 1256 Explorer.EXE 1256 Explorer.EXE 1256 Explorer.EXE -
Suspicious use of SendNotifyMessage 5 IoCs
pid Process 1544 exusltb.exe 1256 Explorer.EXE 1256 Explorer.EXE 1256 Explorer.EXE 1256 Explorer.EXE -
Suspicious use of SetWindowsHookEx 2 IoCs
pid Process 1544 exusltb.exe 1544 exusltb.exe -
Suspicious use of WriteProcessMemory 20 IoCs
description pid Process procid_target PID 1732 wrote to memory of 1812 1732 taskeng.exe 28 PID 1732 wrote to memory of 1812 1732 taskeng.exe 28 PID 1732 wrote to memory of 1812 1732 taskeng.exe 28 PID 1732 wrote to memory of 1812 1732 taskeng.exe 28 PID 1812 wrote to memory of 576 1812 exusltb.exe 23 PID 576 wrote to memory of 1488 576 svchost.exe 31 PID 576 wrote to memory of 1488 576 svchost.exe 31 PID 576 wrote to memory of 1488 576 svchost.exe 31 PID 1812 wrote to memory of 1256 1812 exusltb.exe 12 PID 1812 wrote to memory of 520 1812 exusltb.exe 32 PID 1812 wrote to memory of 520 1812 exusltb.exe 32 PID 1812 wrote to memory of 520 1812 exusltb.exe 32 PID 1812 wrote to memory of 520 1812 exusltb.exe 32 PID 1812 wrote to memory of 1544 1812 exusltb.exe 34 PID 1812 wrote to memory of 1544 1812 exusltb.exe 34 PID 1812 wrote to memory of 1544 1812 exusltb.exe 34 PID 1812 wrote to memory of 1544 1812 exusltb.exe 34 PID 576 wrote to memory of 108 576 svchost.exe 35 PID 576 wrote to memory of 108 576 svchost.exe 35 PID 576 wrote to memory of 108 576 svchost.exe 35
Processes
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C:\Windows\Explorer.EXEC:\Windows\Explorer.EXE1⤵
- Sets desktop wallpaper using registry
- Suspicious behavior: GetForegroundWindowSpam
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of FindShellTrayWindow
- Suspicious use of SendNotifyMessage
PID:1256 -
C:\Users\Admin\AppData\Local\Temp\128a0f0cd5d10f864d5a0741ba25996b2bf74f580ac7918dec6516215801e39a.sample.exe"C:\Users\Admin\AppData\Local\Temp\128a0f0cd5d10f864d5a0741ba25996b2bf74f580ac7918dec6516215801e39a.sample.exe"2⤵
- Suspicious behavior: EnumeratesProcesses
PID:788
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C:\Windows\system32\svchost.exeC:\Windows\system32\svchost.exe -k DcomLaunch1⤵
- Modifies extensions of user files
- Drops desktop.ini file(s)
- Drops file in Program Files directory
- Modifies data under HKEY_USERS
- Suspicious use of WriteProcessMemory
PID:576 -
C:\Windows\system32\DllHost.exeC:\Windows\system32\DllHost.exe /Processid:{AB8902B4-09CA-4BB6-B78D-A8F59079A8D5}2⤵PID:1488
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C:\Windows\system32\DllHost.exeC:\Windows\system32\DllHost.exe /Processid:{3EB3C877-1F16-487C-9050-104DBCD66683}2⤵PID:108
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C:\Windows\system32\taskeng.exetaskeng.exe {32E33CD3-2430-4E2D-8493-D17E78276520} S-1-5-18:NT AUTHORITY\System:Service:1⤵
- Suspicious use of WriteProcessMemory
PID:1732 -
C:\Users\Admin\AppData\Local\Temp\exusltb.exeC:\Users\Admin\AppData\Local\Temp\exusltb.exe2⤵
- Executes dropped EXE
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:1812 -
C:\Windows\SysWOW64\vssadmin.exevssadmin delete shadows all3⤵
- Interacts with shadow copies
PID:520
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C:\Users\Admin\AppData\Local\Temp\exusltb.exe"C:\Users\Admin\AppData\Local\Temp\exusltb.exe" -u3⤵
- Executes dropped EXE
- Checks computer location settings
- Drops file in System32 directory
- Modifies Internet Explorer settings
- Suspicious use of FindShellTrayWindow
- Suspicious use of SendNotifyMessage
- Suspicious use of SetWindowsHookEx
PID:1544
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