Analysis
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max time kernel
147s -
max time network
131s -
platform
windows7_x64 -
resource
win7-en-20211014 -
submitted
20/10/2021, 09:40
Static task
static1
Behavioral task
behavioral1
Sample
B.exe
Resource
win7-en-20211014
Behavioral task
behavioral2
Sample
B.exe
Resource
win10-en-20210920
Behavioral task
behavioral3
Sample
Build.exe
Resource
win7-en-20211014
Behavioral task
behavioral4
Sample
Build.exe
Resource
win10-en-20210920
Behavioral task
behavioral5
Sample
READ.exe
Resource
win7-en-20211014
Behavioral task
behavioral6
Sample
READ.exe
Resource
win10-en-20210920
Behavioral task
behavioral7
Sample
rb.exe
Resource
win7-en-20211014
Behavioral task
behavioral8
Sample
rb.exe
Resource
win10-en-20210920
General
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Target
Build.exe
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Size
669KB
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MD5
b446b1c86f3d27bb39783f9d3a112a40
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SHA1
d9f66f8db27686f4f3b2c7d17557c84077ac801f
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SHA256
1f5eefc1feb47e11e53f82055ca0921fc1b1299dffa7972c6faeff1904fdad1d
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SHA512
c2b7682c265060c1c62be0b4dceba7fed6882b9fdc9cbbd1d379608a482bf215d81a2a3c03cc2df709bc936ee7d06ff1250dde92808bd0e0d1f1ee3410c35d9a
Malware Config
Extracted
\??\Z:\Boot\HOW_TO_RECOVER_DATA.html
Signatures
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MedusaLocker
Ransomware with several variants first seen in September 2019.
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MedusaLocker Payload 2 IoCs
resource yara_rule behavioral3/files/0x00070000000121ee-61.dat family_medusalocker behavioral3/files/0x00070000000121ee-63.dat family_medusalocker -
Deletes shadow copies 2 TTPs
Ransomware often targets backup files to inhibit system recovery.
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Executes dropped EXE 1 IoCs
pid Process 1528 svhost.exe -
Modifies extensions of user files 3 IoCs
Ransomware generally changes the extension on encrypted files.
description ioc Process File opened for modification C:\Users\Admin\Pictures\InitializeInvoke.tiff Build.exe File renamed C:\Users\Admin\Pictures\InitializeInvoke.tiff => C:\Users\Admin\Pictures\InitializeInvoke.tiff.LOCK Build.exe File renamed C:\Users\Admin\Pictures\RemoveMount.raw => C:\Users\Admin\Pictures\RemoveMount.raw.LOCK Build.exe -
Reads user/profile data of web browsers 2 TTPs
Infostealers often target stored browser data, which can include saved credentials etc.
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description ioc Process Set value (int) \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA = "0" Build.exe -
Drops desktop.ini file(s) 1 IoCs
description ioc Process File opened for modification \??\Z:\$RECYCLE.BIN\S-1-5-21-2955169046-2371869340-1800780948-1000\desktop.ini Build.exe -
Enumerates connected drives 3 TTPs 24 IoCs
Attempts to read the root path of hard drives other than the default C: drive.
description ioc Process File opened (read-only) \??\U: Build.exe File opened (read-only) \??\V: Build.exe File opened (read-only) \??\Z: Build.exe File opened (read-only) \??\I: Build.exe File opened (read-only) \??\O: Build.exe File opened (read-only) \??\R: Build.exe File opened (read-only) \??\M: Build.exe File opened (read-only) \??\N: Build.exe File opened (read-only) \??\T: Build.exe File opened (read-only) \??\W: Build.exe File opened (read-only) \??\A: Build.exe File opened (read-only) \??\F: Build.exe File opened (read-only) \??\H: Build.exe File opened (read-only) \??\G: Build.exe File opened (read-only) \??\J: Build.exe File opened (read-only) \??\Q: Build.exe File opened (read-only) \??\L: Build.exe File opened (read-only) \??\P: Build.exe File opened (read-only) \??\S: Build.exe File opened (read-only) \??\X: Build.exe File opened (read-only) \??\Y: Build.exe File opened (read-only) \??\B: Build.exe File opened (read-only) \??\E: Build.exe File opened (read-only) \??\K: Build.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 3 IoCs
Shadow copies are often targeted by ransomware to inhibit system recovery.
pid Process 1004 vssadmin.exe 1684 vssadmin.exe 1068 vssadmin.exe -
Suspicious behavior: EnumeratesProcesses 64 IoCs
pid Process 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe 1072 Build.exe -
Suspicious use of AdjustPrivilegeToken 63 IoCs
description pid Process Token: SeBackupPrivilege 1488 vssvc.exe Token: SeRestorePrivilege 1488 vssvc.exe Token: SeAuditPrivilege 1488 vssvc.exe Token: SeIncreaseQuotaPrivilege 416 wmic.exe Token: SeSecurityPrivilege 416 wmic.exe Token: SeTakeOwnershipPrivilege 416 wmic.exe Token: SeLoadDriverPrivilege 416 wmic.exe Token: SeSystemProfilePrivilege 416 wmic.exe Token: SeSystemtimePrivilege 416 wmic.exe Token: SeProfSingleProcessPrivilege 416 wmic.exe Token: SeIncBasePriorityPrivilege 416 wmic.exe Token: SeCreatePagefilePrivilege 416 wmic.exe Token: SeBackupPrivilege 416 wmic.exe Token: SeRestorePrivilege 416 wmic.exe Token: SeShutdownPrivilege 416 wmic.exe Token: SeDebugPrivilege 416 wmic.exe Token: SeSystemEnvironmentPrivilege 416 wmic.exe Token: SeRemoteShutdownPrivilege 416 wmic.exe Token: SeUndockPrivilege 416 wmic.exe Token: SeManageVolumePrivilege 416 wmic.exe Token: 33 416 wmic.exe Token: 34 416 wmic.exe Token: 35 416 wmic.exe Token: SeIncreaseQuotaPrivilege 1148 wmic.exe Token: SeSecurityPrivilege 1148 wmic.exe Token: SeTakeOwnershipPrivilege 1148 wmic.exe Token: SeLoadDriverPrivilege 1148 wmic.exe Token: SeSystemProfilePrivilege 1148 wmic.exe Token: SeSystemtimePrivilege 1148 wmic.exe Token: SeProfSingleProcessPrivilege 1148 wmic.exe Token: SeIncBasePriorityPrivilege 1148 wmic.exe Token: SeCreatePagefilePrivilege 1148 wmic.exe Token: SeBackupPrivilege 1148 wmic.exe Token: SeRestorePrivilege 1148 wmic.exe Token: SeShutdownPrivilege 1148 wmic.exe Token: SeDebugPrivilege 1148 wmic.exe Token: SeSystemEnvironmentPrivilege 1148 wmic.exe Token: SeRemoteShutdownPrivilege 1148 wmic.exe Token: SeUndockPrivilege 1148 wmic.exe Token: SeManageVolumePrivilege 1148 wmic.exe Token: 33 1148 wmic.exe Token: 34 1148 wmic.exe Token: 35 1148 wmic.exe Token: SeIncreaseQuotaPrivilege 1720 wmic.exe Token: SeSecurityPrivilege 1720 wmic.exe Token: SeTakeOwnershipPrivilege 1720 wmic.exe Token: SeLoadDriverPrivilege 1720 wmic.exe Token: SeSystemProfilePrivilege 1720 wmic.exe Token: SeSystemtimePrivilege 1720 wmic.exe Token: SeProfSingleProcessPrivilege 1720 wmic.exe Token: SeIncBasePriorityPrivilege 1720 wmic.exe Token: SeCreatePagefilePrivilege 1720 wmic.exe Token: SeBackupPrivilege 1720 wmic.exe Token: SeRestorePrivilege 1720 wmic.exe Token: SeShutdownPrivilege 1720 wmic.exe Token: SeDebugPrivilege 1720 wmic.exe Token: SeSystemEnvironmentPrivilege 1720 wmic.exe Token: SeRemoteShutdownPrivilege 1720 wmic.exe Token: SeUndockPrivilege 1720 wmic.exe Token: SeManageVolumePrivilege 1720 wmic.exe Token: 33 1720 wmic.exe Token: 34 1720 wmic.exe Token: 35 1720 wmic.exe -
Suspicious use of WriteProcessMemory 28 IoCs
description pid Process procid_target PID 1072 wrote to memory of 1684 1072 Build.exe 27 PID 1072 wrote to memory of 1684 1072 Build.exe 27 PID 1072 wrote to memory of 1684 1072 Build.exe 27 PID 1072 wrote to memory of 1684 1072 Build.exe 27 PID 1072 wrote to memory of 416 1072 Build.exe 31 PID 1072 wrote to memory of 416 1072 Build.exe 31 PID 1072 wrote to memory of 416 1072 Build.exe 31 PID 1072 wrote to memory of 416 1072 Build.exe 31 PID 1072 wrote to memory of 1068 1072 Build.exe 33 PID 1072 wrote to memory of 1068 1072 Build.exe 33 PID 1072 wrote to memory of 1068 1072 Build.exe 33 PID 1072 wrote to memory of 1068 1072 Build.exe 33 PID 1072 wrote to memory of 1148 1072 Build.exe 35 PID 1072 wrote to memory of 1148 1072 Build.exe 35 PID 1072 wrote to memory of 1148 1072 Build.exe 35 PID 1072 wrote to memory of 1148 1072 Build.exe 35 PID 1072 wrote to memory of 1004 1072 Build.exe 37 PID 1072 wrote to memory of 1004 1072 Build.exe 37 PID 1072 wrote to memory of 1004 1072 Build.exe 37 PID 1072 wrote to memory of 1004 1072 Build.exe 37 PID 1072 wrote to memory of 1720 1072 Build.exe 39 PID 1072 wrote to memory of 1720 1072 Build.exe 39 PID 1072 wrote to memory of 1720 1072 Build.exe 39 PID 1072 wrote to memory of 1720 1072 Build.exe 39 PID 700 wrote to memory of 1528 700 taskeng.exe 42 PID 700 wrote to memory of 1528 700 taskeng.exe 42 PID 700 wrote to memory of 1528 700 taskeng.exe 42 PID 700 wrote to memory of 1528 700 taskeng.exe 42 -
System policy modification 1 TTPs 3 IoCs
description ioc Process Set value (int) \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLinkedConnections = "1" Build.exe Set value (int) \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\EnableLUA = "0" Build.exe Set value (int) \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\ConsentPromptBehaviorAdmin = "0" Build.exe
Processes
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C:\Users\Admin\AppData\Local\Temp\Build.exe"C:\Users\Admin\AppData\Local\Temp\Build.exe"1⤵
- Modifies extensions of user files
- Checks whether UAC is enabled
- Drops desktop.ini file(s)
- Enumerates connected drives
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of WriteProcessMemory
- System policy modification
PID:1072 -
C:\Windows\SysWOW64\vssadmin.exevssadmin.exe Delete Shadows /All /Quiet2⤵
- Interacts with shadow copies
PID:1684
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C:\Windows\SysWOW64\Wbem\wmic.exewmic.exe SHADOWCOPY /nointeractive2⤵
- Suspicious use of AdjustPrivilegeToken
PID:416
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C:\Windows\SysWOW64\vssadmin.exevssadmin.exe Delete Shadows /All /Quiet2⤵
- Interacts with shadow copies
PID:1068
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C:\Windows\SysWOW64\Wbem\wmic.exewmic.exe SHADOWCOPY /nointeractive2⤵
- Suspicious use of AdjustPrivilegeToken
PID:1148
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C:\Windows\SysWOW64\vssadmin.exevssadmin.exe Delete Shadows /All /Quiet2⤵
- Interacts with shadow copies
PID:1004
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C:\Windows\SysWOW64\Wbem\wmic.exewmic.exe SHADOWCOPY /nointeractive2⤵
- Suspicious use of AdjustPrivilegeToken
PID:1720
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C:\Windows\system32\vssvc.exeC:\Windows\system32\vssvc.exe1⤵
- Suspicious use of AdjustPrivilegeToken
PID:1488
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C:\Windows\system32\taskeng.exetaskeng.exe {127E17C9-FC23-4ECD-B1F2-EA1958070B71} S-1-5-21-2955169046-2371869340-1800780948-1000:UKNHJUQT\Admin:Interactive:[1]1⤵
- Suspicious use of WriteProcessMemory
PID:700 -
C:\Users\Admin\AppData\Roaming\svhost.exeC:\Users\Admin\AppData\Roaming\svhost.exe2⤵
- Executes dropped EXE
PID:1528
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