Analysis
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max time kernel
121s -
max time network
126s -
platform
windows7_x64 -
resource
win7-20241010-en -
resource tags
arch:x64arch:x86image:win7-20241010-enlocale:en-usos:windows7-x64system -
submitted
18-02-2025 17:17
Behavioral task
behavioral1
Sample
YashmaClients.exe
Resource
win7-20241010-en
Behavioral task
behavioral2
Sample
YashmaClients.exe
Resource
win10v2004-20250217-en
General
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Target
YashmaClients.exe
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Size
129KB
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MD5
15fba1967c6bcd09520811dfe34a159b
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SHA1
dec383511b8f764f3222798586ee22f0fda0331c
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SHA256
a83e19610aa006d4789bb38e18b609538befb16a1df30e1205e0c38aeda089e4
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SHA512
f2990e7c548f0bb18e84aeff62a38ce5d97046b44313dfda948d51efe4eac7c855b71437b57cb2e9f48453a27570559c3d6ab8349be1fdbaac44b2ef79f9dc59
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SSDEEP
768:x7zxAmU2NJ1KQxJPho9aT3e82hQfMCwRhOF15utoS:xND3x7Pq9m3ZsA/wCFLS
Malware Config
Signatures
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Chaos
Ransomware family first seen in June 2021.
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Chaos Ransomware 3 IoCs
resource yara_rule behavioral1/memory/2904-1-0x0000000000230000-0x0000000000256000-memory.dmp family_chaos behavioral1/files/0x000d000000012263-6.dat family_chaos behavioral1/memory/2868-8-0x00000000002A0000-0x00000000002C6000-memory.dmp family_chaos -
Chaos family
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Deletes shadow copies 3 TTPs
Ransomware often targets backup files to inhibit system recovery.
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Modifies boot configuration data using bcdedit 1 TTPs 2 IoCs
pid Process 3016 bcdedit.exe 1560 bcdedit.exe -
pid Process 3000 wbadmin.exe -
Disables Task Manager via registry modification
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Drops startup file 2 IoCs
description ioc Process File created C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\read_it.txt svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\desktop.ini svchost.exe -
Executes dropped EXE 1 IoCs
pid Process 2868 svchost.exe -
Reads user/profile data of web browsers 3 TTPs
Infostealers often target stored browser data, which can include saved credentials etc.
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Adds Run key to start application 2 TTPs 1 IoCs
description ioc Process Set value (str) \REGISTRY\USER\S-1-5-21-3692679935-4019334568-335155002-1000\Software\Microsoft\Windows\CurrentVersion\Run\UpdateTask = "C:\\Users\\Admin\\AppData\\Roaming\\svchost.exe" svchost.exe -
Drops desktop.ini file(s) 64 IoCs
description ioc Process File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\Accessories\Desktop.ini svchost.exe File opened for modification C:\Users\Admin\Pictures\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Searches\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Windows\Burn\Burn\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.IE5\G0UQMQ1C\desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\Administrative Tools\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Internet Explorer\Quick Launch\desktop.ini svchost.exe File opened for modification C:\Users\Public\Recorded TV\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Windows\Temporary Internet Files\desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Ringtones\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Windows\History\History.IE5\desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\Accessories\System Tools\Desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\desktop.ini svchost.exe File opened for modification C:\Users\Default\AppData\Roaming\Microsoft\Internet Explorer\Quick Launch\desktop.ini svchost.exe File opened for modification C:\Users\Default\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Maintenance\Desktop.ini svchost.exe File opened for modification C:\Users\Public\Desktop\desktop.ini svchost.exe File opened for modification C:\Users\Public\Downloads\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Libraries\desktop.ini svchost.exe File opened for modification C:\Users\Public\Pictures\desktop.ini svchost.exe File opened for modification C:\Users\Public\Recorded TV\Sample Media\desktop.ini svchost.exe File opened for modification C:\Users\Default\AppData\Roaming\Microsoft\Windows\SendTo\Desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.IE5\BBWU148F\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Accessories\Desktop.ini svchost.exe File opened for modification C:\Users\Default\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Accessories\Desktop.ini svchost.exe File opened for modification C:\Users\Public\Music\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Accessories\Accessibility\Desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Administrative Tools\desktop.ini svchost.exe File opened for modification F:\$RECYCLE.BIN\S-1-5-21-3692679935-4019334568-335155002-1000\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Windows Mail\Stationery\Desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\Startup\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Favorites\Links\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Videos\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Internet Explorer\Quick Launch\User Pinned\TaskBar\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Accessories\System Tools\Desktop.ini svchost.exe File opened for modification C:\Users\Default\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Accessories\System Tools\Desktop.ini svchost.exe File opened for modification C:\Users\Admin\Downloads\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Desktop\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Documents\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\SendTo\Desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Windows\History\desktop.ini svchost.exe File opened for modification C:\Users\Public\Documents\desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\Accessories\Tablet PC\Desktop.ini svchost.exe File opened for modification C:\Users\Admin\Music\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Maintenance\Desktop.ini svchost.exe File opened for modification C:\Users\Public\Pictures\Sample Pictures\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Feeds Cache\5O2ZS8DL\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.IE5\4TDQSVWU\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.IE5\desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\Maintenance\Desktop.ini svchost.exe File opened for modification C:\Users\Admin\Contacts\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Favorites\desktop.ini svchost.exe File opened for modification C:\Users\Admin\Favorites\Links for United States\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Feeds Cache\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Feeds Cache\1U7Y9BT8\desktop.ini svchost.exe File opened for modification C:\Users\Public\Music\Sample Music\desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\Accessories\Accessibility\Desktop.ini svchost.exe File opened for modification C:\Users\All Users\Microsoft\Windows\Start Menu\Programs\Accessories\Windows PowerShell\desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Recent\desktop.ini svchost.exe File opened for modification C:\Users\Default\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Accessories\Accessibility\Desktop.ini svchost.exe File opened for modification C:\Users\Admin\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.IE5\SEGJVAZC\desktop.ini svchost.exe File opened for modification C:\Users\Public\Videos\desktop.ini svchost.exe -
Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s).
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Interacts with shadow copies 3 TTPs 1 IoCs
Shadow copies are often targeted by ransomware to inhibit system recovery.
pid Process 2852 vssadmin.exe -
Opens file in notepad (likely ransom note) 1 IoCs
pid Process 2432 NOTEPAD.EXE -
Suspicious behavior: AddClipboardFormatListener 1 IoCs
pid Process 2868 svchost.exe -
Suspicious behavior: EnumeratesProcesses 6 IoCs
pid Process 2904 YashmaClients.exe 2904 YashmaClients.exe 2904 YashmaClients.exe 2868 svchost.exe 2868 svchost.exe 2868 svchost.exe -
Suspicious use of AdjustPrivilegeToken 48 IoCs
description pid Process Token: SeDebugPrivilege 2904 YashmaClients.exe Token: SeDebugPrivilege 2868 svchost.exe Token: SeBackupPrivilege 2888 vssvc.exe Token: SeRestorePrivilege 2888 vssvc.exe Token: SeAuditPrivilege 2888 vssvc.exe Token: SeIncreaseQuotaPrivilege 112 WMIC.exe Token: SeSecurityPrivilege 112 WMIC.exe Token: SeTakeOwnershipPrivilege 112 WMIC.exe Token: SeLoadDriverPrivilege 112 WMIC.exe Token: SeSystemProfilePrivilege 112 WMIC.exe Token: SeSystemtimePrivilege 112 WMIC.exe Token: SeProfSingleProcessPrivilege 112 WMIC.exe Token: SeIncBasePriorityPrivilege 112 WMIC.exe Token: SeCreatePagefilePrivilege 112 WMIC.exe Token: SeBackupPrivilege 112 WMIC.exe Token: SeRestorePrivilege 112 WMIC.exe Token: SeShutdownPrivilege 112 WMIC.exe Token: SeDebugPrivilege 112 WMIC.exe Token: SeSystemEnvironmentPrivilege 112 WMIC.exe Token: SeRemoteShutdownPrivilege 112 WMIC.exe Token: SeUndockPrivilege 112 WMIC.exe Token: SeManageVolumePrivilege 112 WMIC.exe Token: 33 112 WMIC.exe Token: 34 112 WMIC.exe Token: 35 112 WMIC.exe Token: SeIncreaseQuotaPrivilege 112 WMIC.exe Token: SeSecurityPrivilege 112 WMIC.exe Token: SeTakeOwnershipPrivilege 112 WMIC.exe Token: SeLoadDriverPrivilege 112 WMIC.exe Token: SeSystemProfilePrivilege 112 WMIC.exe Token: SeSystemtimePrivilege 112 WMIC.exe Token: SeProfSingleProcessPrivilege 112 WMIC.exe Token: SeIncBasePriorityPrivilege 112 WMIC.exe Token: SeCreatePagefilePrivilege 112 WMIC.exe Token: SeBackupPrivilege 112 WMIC.exe Token: SeRestorePrivilege 112 WMIC.exe Token: SeShutdownPrivilege 112 WMIC.exe Token: SeDebugPrivilege 112 WMIC.exe Token: SeSystemEnvironmentPrivilege 112 WMIC.exe Token: SeRemoteShutdownPrivilege 112 WMIC.exe Token: SeUndockPrivilege 112 WMIC.exe Token: SeManageVolumePrivilege 112 WMIC.exe Token: 33 112 WMIC.exe Token: 34 112 WMIC.exe Token: 35 112 WMIC.exe Token: SeBackupPrivilege 2096 wbengine.exe Token: SeRestorePrivilege 2096 wbengine.exe Token: SeSecurityPrivilege 2096 wbengine.exe -
Suspicious use of WriteProcessMemory 30 IoCs
description pid Process procid_target PID 2904 wrote to memory of 2868 2904 YashmaClients.exe 30 PID 2904 wrote to memory of 2868 2904 YashmaClients.exe 30 PID 2904 wrote to memory of 2868 2904 YashmaClients.exe 30 PID 2868 wrote to memory of 2712 2868 svchost.exe 31 PID 2868 wrote to memory of 2712 2868 svchost.exe 31 PID 2868 wrote to memory of 2712 2868 svchost.exe 31 PID 2712 wrote to memory of 2852 2712 cmd.exe 33 PID 2712 wrote to memory of 2852 2712 cmd.exe 33 PID 2712 wrote to memory of 2852 2712 cmd.exe 33 PID 2712 wrote to memory of 112 2712 cmd.exe 36 PID 2712 wrote to memory of 112 2712 cmd.exe 36 PID 2712 wrote to memory of 112 2712 cmd.exe 36 PID 2868 wrote to memory of 2388 2868 svchost.exe 38 PID 2868 wrote to memory of 2388 2868 svchost.exe 38 PID 2868 wrote to memory of 2388 2868 svchost.exe 38 PID 2388 wrote to memory of 3016 2388 cmd.exe 40 PID 2388 wrote to memory of 3016 2388 cmd.exe 40 PID 2388 wrote to memory of 3016 2388 cmd.exe 40 PID 2388 wrote to memory of 1560 2388 cmd.exe 41 PID 2388 wrote to memory of 1560 2388 cmd.exe 41 PID 2388 wrote to memory of 1560 2388 cmd.exe 41 PID 2868 wrote to memory of 836 2868 svchost.exe 42 PID 2868 wrote to memory of 836 2868 svchost.exe 42 PID 2868 wrote to memory of 836 2868 svchost.exe 42 PID 836 wrote to memory of 3000 836 cmd.exe 44 PID 836 wrote to memory of 3000 836 cmd.exe 44 PID 836 wrote to memory of 3000 836 cmd.exe 44 PID 2868 wrote to memory of 2432 2868 svchost.exe 49 PID 2868 wrote to memory of 2432 2868 svchost.exe 49 PID 2868 wrote to memory of 2432 2868 svchost.exe 49 -
Uses Task Scheduler COM API 1 TTPs
The Task Scheduler COM API can be used to schedule applications to run on boot or at set times.
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Uses Volume Shadow Copy service COM API
The Volume Shadow Copy service is used to manage backups/snapshots.
Processes
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C:\Users\Admin\AppData\Local\Temp\YashmaClients.exe"C:\Users\Admin\AppData\Local\Temp\YashmaClients.exe"1⤵
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:2904 -
C:\Users\Admin\AppData\Roaming\svchost.exe"C:\Users\Admin\AppData\Roaming\svchost.exe"2⤵
- Drops startup file
- Executes dropped EXE
- Adds Run key to start application
- Drops desktop.ini file(s)
- Suspicious behavior: AddClipboardFormatListener
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:2868 -
C:\Windows\System32\cmd.exe"C:\Windows\System32\cmd.exe" /C vssadmin delete shadows /all /quiet & wmic shadowcopy delete3⤵
- Suspicious use of WriteProcessMemory
PID:2712 -
C:\Windows\system32\vssadmin.exevssadmin delete shadows /all /quiet4⤵
- Interacts with shadow copies
PID:2852
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C:\Windows\System32\Wbem\WMIC.exewmic shadowcopy delete4⤵
- Suspicious use of AdjustPrivilegeToken
PID:112
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C:\Windows\System32\cmd.exe"C:\Windows\System32\cmd.exe" /C bcdedit /set {default} bootstatuspolicy ignoreallfailures & bcdedit /set {default} recoveryenabled no3⤵
- Suspicious use of WriteProcessMemory
PID:2388 -
C:\Windows\system32\bcdedit.exebcdedit /set {default} bootstatuspolicy ignoreallfailures4⤵
- Modifies boot configuration data using bcdedit
PID:3016
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C:\Windows\system32\bcdedit.exebcdedit /set {default} recoveryenabled no4⤵
- Modifies boot configuration data using bcdedit
PID:1560
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C:\Windows\System32\cmd.exe"C:\Windows\System32\cmd.exe" /C wbadmin delete catalog -quiet3⤵
- Suspicious use of WriteProcessMemory
PID:836 -
C:\Windows\system32\wbadmin.exewbadmin delete catalog -quiet4⤵
- Deletes backup catalog
PID:3000
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C:\Windows\system32\NOTEPAD.EXE"C:\Windows\system32\NOTEPAD.EXE" C:\Users\Admin\AppData\Roaming\read_it.txt3⤵
- Opens file in notepad (likely ransom note)
PID:2432
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C:\Windows\system32\vssvc.exeC:\Windows\system32\vssvc.exe1⤵
- Suspicious use of AdjustPrivilegeToken
PID:2888
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C:\Windows\system32\wbengine.exe"C:\Windows\system32\wbengine.exe"1⤵
- Suspicious use of AdjustPrivilegeToken
PID:2096
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C:\Windows\System32\vdsldr.exeC:\Windows\System32\vdsldr.exe -Embedding1⤵PID:2436
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C:\Windows\System32\vds.exeC:\Windows\System32\vds.exe1⤵PID:1756
Network
MITRE ATT&CK Enterprise v15
Privilege Escalation
Boot or Logon Autostart Execution
1Registry Run Keys / Startup Folder
1Defense Evasion
Direct Volume Access
1Indicator Removal
3File Deletion
3Modify Registry
1Replay Monitor
Loading Replay Monitor...
Downloads
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Filesize
342B
MD5ee3b113d32ed8c4ee76443d3b81a72d3
SHA14042e1a579366b7c62ea5e75b7eff031b408d7bd
SHA25602132ce5b64b9bbbf77f1e6015569583f015039abb8f2ab021c9db1ae5116383
SHA512a2c00d94871d6842853ac42eb7c84c533dac1f7b875b4f4911e1298363cf703a85f64fb398bd760b51c819094f7db0047000660f0fd54ec61359a998ba5fd74b
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Filesize
129KB
MD515fba1967c6bcd09520811dfe34a159b
SHA1dec383511b8f764f3222798586ee22f0fda0331c
SHA256a83e19610aa006d4789bb38e18b609538befb16a1df30e1205e0c38aeda089e4
SHA512f2990e7c548f0bb18e84aeff62a38ce5d97046b44313dfda948d51efe4eac7c855b71437b57cb2e9f48453a27570559c3d6ab8349be1fdbaac44b2ef79f9dc59
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Filesize
1B
MD5d1457b72c3fb323a2671125aef3eab5d
SHA15bab61eb53176449e25c2c82f172b82cb13ffb9d
SHA2568a8de823d5ed3e12746a62ef169bcf372be0ca44f0a1236abc35df05d96928e1
SHA512ca63c07ad35d8c9fb0c92d6146759b122d4ec5d3f67ebe2f30ddb69f9e6c9fd3bf31a5e408b08f1d4d9cd68120cced9e57f010bef3cde97653fed5470da7d1a0