Resubmissions
06-07-2021 11:37
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210704-587ycgna36 1004-07-2021 16:29
210704-d622hysdcx 1003-07-2021 14:55
210703-cggr9ffskx 10Analysis
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max time kernel
19s -
max time network
21s -
platform
windows10_x64 -
resource
win10v20210408 -
submitted
04-07-2021 16:29
Static task
static1
Behavioral task
behavioral1
Sample
revil_kasaya.exe
Resource
win7v20210410
Behavioral task
behavioral2
Sample
revil_kasaya.exe
Resource
win10v20210408
General
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Target
revil_kasaya.exe
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Size
136KB
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MD5
94d087166651c0020a9e6cc2fdacdc0c
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SHA1
99be22569ba9b1e49d3fd36f65faa6795672fcc0
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SHA256
9b11711efed24b3c6723521a7d7eb4a52e4914db7420e278aa36e727459d59dd
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SHA512
0f5a413e57e4cedf0a8df3b33cda3c2c0732ded58c367633e8677bf88786eb786b85c97420fda150fecb68db74dc00f77064c3ea77d00f53904413c9ea3a93ba
Malware Config
Extracted
C:\79f61-readme.txt
http://aplebzu47wgazapdqks6vrcv6zcnjppkbxbr6wketf56nf6aq2nmyoyd.onion/731FD902B6FACA31
http://decoder.re/731FD902B6FACA31
Signatures
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Modifies Windows Firewall 1 TTPs
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Modifies extensions of user files 14 IoCs
Ransomware generally changes the extension on encrypted files.
description ioc Process File renamed C:\Users\Admin\Pictures\GrantMount.tif => \??\c:\users\admin\pictures\GrantMount.tif.79f61 revil_kasaya.exe File renamed C:\Users\Admin\Pictures\ImportEnter.raw => \??\c:\users\admin\pictures\ImportEnter.raw.79f61 revil_kasaya.exe File renamed C:\Users\Admin\Pictures\MoveSave.crw => \??\c:\users\admin\pictures\MoveSave.crw.79f61 revil_kasaya.exe File renamed C:\Users\Admin\Pictures\RenameGroup.raw => \??\c:\users\admin\pictures\RenameGroup.raw.79f61 revil_kasaya.exe File opened for modification \??\c:\users\admin\pictures\BlockImport.tiff revil_kasaya.exe File renamed C:\Users\Admin\Pictures\SetDisconnect.png => \??\c:\users\admin\pictures\SetDisconnect.png.79f61 revil_kasaya.exe File renamed C:\Users\Admin\Pictures\InstallClear.crw => \??\c:\users\admin\pictures\InstallClear.crw.79f61 revil_kasaya.exe File renamed C:\Users\Admin\Pictures\ResetGroup.png => \??\c:\users\admin\pictures\ResetGroup.png.79f61 revil_kasaya.exe File renamed C:\Users\Admin\Pictures\SearchSelect.tif => \??\c:\users\admin\pictures\SearchSelect.tif.79f61 revil_kasaya.exe File renamed C:\Users\Admin\Pictures\UpdateStart.png => \??\c:\users\admin\pictures\UpdateStart.png.79f61 revil_kasaya.exe File renamed C:\Users\Admin\Pictures\BlockImport.tiff => \??\c:\users\admin\pictures\BlockImport.tiff.79f61 revil_kasaya.exe File renamed C:\Users\Admin\Pictures\DebugTrace.tif => \??\c:\users\admin\pictures\DebugTrace.tif.79f61 revil_kasaya.exe File renamed C:\Users\Admin\Pictures\ResetRead.raw => \??\c:\users\admin\pictures\ResetRead.raw.79f61 revil_kasaya.exe File renamed C:\Users\Admin\Pictures\UseExport.png => \??\c:\users\admin\pictures\UseExport.png.79f61 revil_kasaya.exe -
Enumerates connected drives 3 TTPs 25 IoCs
Attempts to read the root path of hard drives other than the default C: drive.
description ioc Process File opened (read-only) \??\J: revil_kasaya.exe File opened (read-only) \??\V: revil_kasaya.exe File opened (read-only) \??\X: revil_kasaya.exe File opened (read-only) \??\Y: revil_kasaya.exe File opened (read-only) \??\A: revil_kasaya.exe File opened (read-only) \??\F: revil_kasaya.exe File opened (read-only) \??\H: revil_kasaya.exe File opened (read-only) \??\I: revil_kasaya.exe File opened (read-only) \??\N: revil_kasaya.exe File opened (read-only) \??\O: revil_kasaya.exe File opened (read-only) \??\T: revil_kasaya.exe File opened (read-only) \??\U: revil_kasaya.exe File opened (read-only) \??\D: revil_kasaya.exe File opened (read-only) \??\K: revil_kasaya.exe File opened (read-only) \??\Q: revil_kasaya.exe File opened (read-only) \??\R: revil_kasaya.exe File opened (read-only) \??\S: revil_kasaya.exe File opened (read-only) \??\W: revil_kasaya.exe File opened (read-only) \??\B: revil_kasaya.exe File opened (read-only) \??\E: revil_kasaya.exe File opened (read-only) \??\G: revil_kasaya.exe File opened (read-only) \??\L: revil_kasaya.exe File opened (read-only) \??\M: revil_kasaya.exe File opened (read-only) \??\P: revil_kasaya.exe File opened (read-only) \??\Z: revil_kasaya.exe -
Sets desktop wallpaper using registry 2 TTPs 1 IoCs
description ioc Process Set value (str) \REGISTRY\USER\S-1-5-21-1594587808-2047097707-2163810515-1000\Control Panel\Desktop\Wallpaper = "C:\\Users\\Admin\\AppData\\Local\\Temp\\54520g.bmp" revil_kasaya.exe -
Drops file in Program Files directory 37 IoCs
description ioc Process File opened for modification \??\c:\program files\CheckpointMount.m4v revil_kasaya.exe File opened for modification \??\c:\program files\CompareRegister.ini revil_kasaya.exe File opened for modification \??\c:\program files\LimitRemove.png revil_kasaya.exe File opened for modification \??\c:\program files\RegisterConfirm.M2V revil_kasaya.exe File created \??\c:\program files (x86)\79f61-readme.txt revil_kasaya.exe File opened for modification \??\c:\program files\ReceiveFormat.M2V revil_kasaya.exe File opened for modification \??\c:\program files\RestartConvertTo.pptm revil_kasaya.exe File opened for modification \??\c:\program files\LockPublish.fon revil_kasaya.exe File opened for modification \??\c:\program files\PingGroup.htm revil_kasaya.exe File opened for modification \??\c:\program files\SkipStep.dotx revil_kasaya.exe File opened for modification \??\c:\program files\UnpublishDebug.mid revil_kasaya.exe File created \??\c:\program files\tmp revil_kasaya.exe File opened for modification \??\c:\program files\CompleteLimit.reg revil_kasaya.exe File opened for modification \??\c:\program files\ConfirmDisconnect.mp2 revil_kasaya.exe File opened for modification \??\c:\program files\CopyWrite.gif revil_kasaya.exe File opened for modification \??\c:\program files\TraceResume.DVR-MS revil_kasaya.exe File opened for modification \??\c:\program files\ClearEnter.MTS revil_kasaya.exe File opened for modification \??\c:\program files\DenyNew.inf revil_kasaya.exe File opened for modification \??\c:\program files\SearchSync.midi revil_kasaya.exe File opened for modification \??\c:\program files\SwitchBackup.i64 revil_kasaya.exe File opened for modification \??\c:\program files\DebugWatch.m1v revil_kasaya.exe File opened for modification \??\c:\program files\DismountWatch.xlt revil_kasaya.exe File opened for modification \??\c:\program files\WriteDismount.jpeg revil_kasaya.exe File created \??\c:\program files\79f61-readme.txt revil_kasaya.exe File created \??\c:\program files (x86)\tmp revil_kasaya.exe File opened for modification \??\c:\program files\CompleteInvoke.mpeg2 revil_kasaya.exe File opened for modification \??\c:\program files\ConvertEnable.3gp revil_kasaya.exe File opened for modification \??\c:\program files\SplitDisconnect.rtf revil_kasaya.exe File opened for modification \??\c:\program files\SplitEnter.7z revil_kasaya.exe File opened for modification \??\c:\program files\WatchImport.7z revil_kasaya.exe File opened for modification \??\c:\program files\ClearConvertTo.temp revil_kasaya.exe File opened for modification \??\c:\program files\ReadStop.eprtx revil_kasaya.exe File opened for modification \??\c:\program files\RestoreConnect.pcx revil_kasaya.exe File opened for modification \??\c:\program files\SelectReceive.xlt revil_kasaya.exe File opened for modification \??\c:\program files\ExpandSend.otf revil_kasaya.exe File opened for modification \??\c:\program files\WaitUnpublish.txt revil_kasaya.exe File opened for modification \??\c:\program files\CompressRestart.zip revil_kasaya.exe -
Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s). Likely ransomware behaviour.
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Suspicious behavior: EnumeratesProcesses 10 IoCs
pid Process 664 revil_kasaya.exe 664 revil_kasaya.exe 664 revil_kasaya.exe 664 revil_kasaya.exe 664 revil_kasaya.exe 664 revil_kasaya.exe 664 revil_kasaya.exe 664 revil_kasaya.exe 664 revil_kasaya.exe 664 revil_kasaya.exe -
Suspicious use of AdjustPrivilegeToken 5 IoCs
description pid Process Token: SeDebugPrivilege 664 revil_kasaya.exe Token: SeTakeOwnershipPrivilege 664 revil_kasaya.exe Token: SeBackupPrivilege 628 vssvc.exe Token: SeRestorePrivilege 628 vssvc.exe Token: SeAuditPrivilege 628 vssvc.exe -
Suspicious use of WriteProcessMemory 3 IoCs
description pid Process procid_target PID 664 wrote to memory of 508 664 revil_kasaya.exe 77 PID 664 wrote to memory of 508 664 revil_kasaya.exe 77 PID 664 wrote to memory of 508 664 revil_kasaya.exe 77
Processes
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C:\Users\Admin\AppData\Local\Temp\revil_kasaya.exe"C:\Users\Admin\AppData\Local\Temp\revil_kasaya.exe"1⤵
- Modifies extensions of user files
- Enumerates connected drives
- Sets desktop wallpaper using registry
- Drops file in Program Files directory
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:664 -
C:\Windows\SysWOW64\netsh.exenetsh advfirewall firewall set rule group="Network Discovery" new enable=Yes2⤵PID:508
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C:\Windows\system32\wbem\unsecapp.exeC:\Windows\system32\wbem\unsecapp.exe -Embedding1⤵PID:2388
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C:\Windows\system32\vssvc.exeC:\Windows\system32\vssvc.exe1⤵
- Suspicious use of AdjustPrivilegeToken
PID:628