Analysis
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max time kernel
119s -
max time network
110s -
platform
windows10-2004_x64 -
resource
win10v2004-20240802-en -
resource tags
arch:x64arch:x86image:win10v2004-20240802-enlocale:en-usos:windows10-2004-x64system -
submitted
17-08-2024 22:09
Behavioral task
behavioral1
Sample
31939ac5200472a417faf3b6c4504a40N.exe
Resource
win7-20240704-en
Behavioral task
behavioral2
Sample
31939ac5200472a417faf3b6c4504a40N.exe
Resource
win10v2004-20240802-en
General
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Target
31939ac5200472a417faf3b6c4504a40N.exe
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Size
63KB
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MD5
31939ac5200472a417faf3b6c4504a40
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SHA1
f467058b6cbde29bca7bf66d3e182abce2a0f5f6
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SHA256
2918cbdd03bd34774fdf83732c1dd0f6e889d69d00de2afec7e2964d4744af53
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SHA512
53d20da3fb6a39b6069631dd1d281e8621f9ff562f3e5a6d3c32495e48539d02da737b51dab87fb1f17df444d9d49739c1f7115b2e15211d494c2ce66c5b842e
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SSDEEP
768:rAUJmQCcmLCXQq6fsKiJYsIkjJVzqsVG5kuGKQLddOW/34WvLTkXWV:sUNHFKQbIkHvGMdOo40Td
Malware Config
Signatures
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description ioc Process Set value (int) \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Security Center\AntiVirusDisableNotify = "5120" rmass.exe Set value (int) \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Security Center\FirewallDisableNotify = "5120" rmass.exe Set value (int) \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Security Center\UpdatesDisableNotify = "5120" rmass.exe Set value (int) \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Security Center\AntiVirusOverride = "5120" rmass.exe -
Boot or Logon Autostart Execution: Active Setup 2 TTPs 4 IoCs
Adversaries may achieve persistence by adding a Registry key to the Active Setup of the local machine.
description ioc Process Key created \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Active Setup\Installed Components\{45524851-4a56-5951-4552-48514A565951} rmass.exe Set value (str) \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Active Setup\Installed Components\{45524851-4a56-5951-4552-48514A565951}\01234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123 = "a" rmass.exe Set value (int) \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Active Setup\Installed Components\{45524851-4a56-5951-4552-48514A565951}\IsInstalled = "1" rmass.exe Set value (str) \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Active Setup\Installed Components\{45524851-4a56-5951-4552-48514A565951}\StubPath = "C:\\Windows\\system32\\ahuy.exe" rmass.exe -
Drops file in Drivers directory 1 IoCs
description ioc Process File opened for modification C:\Windows\system32\drivers\etc\hosts rmass.exe -
Event Triggered Execution: Image File Execution Options Injection 1 TTPs 3 IoCs
description ioc Process Key created \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\explorer.exe rmass.exe Set value (str) \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\explorer.exe\0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890 = "a" rmass.exe Set value (str) \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\explorer.exe\Debugger = "C:\\Windows\\system32\\ntdbg.exe" rmass.exe -
Executes dropped EXE 2 IoCs
pid Process 4624 rmass.exe 3232 rmass.exe -
resource yara_rule behavioral2/memory/2516-0-0x0000000000400000-0x0000000000412000-memory.dmp upx behavioral2/files/0x0009000000023426-5.dat upx behavioral2/memory/2516-11-0x0000000000400000-0x0000000000412000-memory.dmp upx behavioral2/memory/4624-41-0x0000000000400000-0x0000000000412000-memory.dmp upx behavioral2/memory/3232-46-0x0000000000400000-0x0000000000412000-memory.dmp upx -
description ioc Process Set value (int) \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Security Center\FirewallDisableNotify = "5120" rmass.exe Set value (int) \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Security Center\UpdatesDisableNotify = "5120" rmass.exe Set value (int) \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Security Center\AntiVirusOverride = "5120" rmass.exe Set value (int) \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Security Center\AntiVirusDisableNotify = "5120" rmass.exe -
description ioc Process Delete value \REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\explorer.exe\Debugger rmass.exe -
Modifies WinLogon 2 TTPs 5 IoCs
description ioc Process Key created \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\{BC84DF00-BC38-9902-8082-6FCBF2D87A0B} rmass.exe Key created \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify rmass.exe Set value (str) \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\{BC84DF00-BC38-9902-8082-6FCBF2D87A0B}\012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345 = "a" rmass.exe Set value (str) \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\{BC84DF00-BC38-9902-8082-6FCBF2D87A0B}\DLLName = "C:\\Windows\\system32\\RECOVER32.DLL" rmass.exe Set value (str) \REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\{BC84DF00-BC38-9902-8082-6FCBF2D87A0B}\Startup = "Startup" rmass.exe -
Drops file in System32 directory 12 IoCs
description ioc Process File created C:\Windows\SysWOW64\rmass.exe 31939ac5200472a417faf3b6c4504a40N.exe File opened for modification C:\Windows\SysWOW64\ahuy.exe rmass.exe File opened for modification C:\Windows\SysWOW64\RECOVER32.DLL rmass.exe File opened for modification C:\Windows\SysWOW64\rmass.exe 31939ac5200472a417faf3b6c4504a40N.exe File opened for modification C:\Windows\SysWOW64\ntdbg.exe rmass.exe File created C:\Windows\SysWOW64\ntdbg.exe rmass.exe File created C:\Windows\SysWOW64\ahuy.exe rmass.exe File created C:\Windows\SysWOW64\RECOVER32.DLL rmass.exe File opened for modification C:\Windows\SysWOW64\winrnt.exe rmass.exe File opened for modification C:\Windows\SysWOW64\aset32.exe rmass.exe File opened for modification C:\Windows\SysWOW64\idbg32.exe rmass.exe File opened for modification C:\Windows\SysWOW64\rmass.exe rmass.exe -
Drops file in Program Files directory 3 IoCs
description ioc Process File opened for modification C:\Program Files (x86)\Common Files\System\aset32.exe rmass.exe File opened for modification C:\Program Files (x86)\Common Files\System\idbg32.exe rmass.exe File opened for modification C:\Program Files (x86)\Common Files\System\winrnt.exe rmass.exe -
System Location Discovery: System Language Discovery 1 TTPs 3 IoCs
Attempt gather information about the system language of a victim in order to infer the geographical location of that host.
description ioc Process Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language 31939ac5200472a417faf3b6c4504a40N.exe Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language rmass.exe Key opened \REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language rmass.exe -
Suspicious behavior: EnumeratesProcesses 8 IoCs
pid Process 4624 rmass.exe 4624 rmass.exe 4624 rmass.exe 4624 rmass.exe 4624 rmass.exe 4624 rmass.exe 3232 rmass.exe 3232 rmass.exe -
Suspicious use of AdjustPrivilegeToken 2 IoCs
description pid Process Token: SeDebugPrivilege 2516 31939ac5200472a417faf3b6c4504a40N.exe Token: SeDebugPrivilege 4624 rmass.exe -
Suspicious use of WriteProcessMemory 8 IoCs
description pid Process procid_target PID 2516 wrote to memory of 4624 2516 31939ac5200472a417faf3b6c4504a40N.exe 84 PID 2516 wrote to memory of 4624 2516 31939ac5200472a417faf3b6c4504a40N.exe 84 PID 2516 wrote to memory of 4624 2516 31939ac5200472a417faf3b6c4504a40N.exe 84 PID 4624 wrote to memory of 616 4624 rmass.exe 5 PID 4624 wrote to memory of 3424 4624 rmass.exe 56 PID 4624 wrote to memory of 3232 4624 rmass.exe 85 PID 4624 wrote to memory of 3232 4624 rmass.exe 85 PID 4624 wrote to memory of 3232 4624 rmass.exe 85
Processes
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C:\Windows\system32\winlogon.exewinlogon.exe1⤵PID:616
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C:\Windows\Explorer.EXEC:\Windows\Explorer.EXE1⤵PID:3424
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C:\Users\Admin\AppData\Local\Temp\31939ac5200472a417faf3b6c4504a40N.exe"C:\Users\Admin\AppData\Local\Temp\31939ac5200472a417faf3b6c4504a40N.exe"2⤵
- Drops file in System32 directory
- System Location Discovery: System Language Discovery
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:2516 -
C:\Windows\SysWOW64\rmass.exe"C:\Windows\system32\rmass.exe"3⤵
- Windows security bypass
- Boot or Logon Autostart Execution: Active Setup
- Drops file in Drivers directory
- Event Triggered Execution: Image File Execution Options Injection
- Executes dropped EXE
- Windows security modification
- Indicator Removal: Clear Persistence
- Modifies WinLogon
- Drops file in System32 directory
- Drops file in Program Files directory
- System Location Discovery: System Language Discovery
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
- Suspicious use of WriteProcessMemory
PID:4624 -
C:\Windows\SysWOW64\rmass.exe--k33p4⤵
- Executes dropped EXE
- System Location Discovery: System Language Discovery
- Suspicious behavior: EnumeratesProcesses
PID:3232
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Network
MITRE ATT&CK Enterprise v15
Persistence
Boot or Logon Autostart Execution
2Active Setup
1Winlogon Helper DLL
1Event Triggered Execution
1Image File Execution Options Injection
1Privilege Escalation
Boot or Logon Autostart Execution
2Active Setup
1Winlogon Helper DLL
1Event Triggered Execution
1Image File Execution Options Injection
1Replay Monitor
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Downloads
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Filesize
5KB
MD52b2c28a7a01f9584fe220ef84003427f
SHA15fc023df0b5064045eb8de7f2dbe26f07f6fec70
SHA2569e00af53b1d0c0f5270d94a666d95aa7b4dcb9fea49487c210c055c9dcfcc9eb
SHA51239192a8a91dec1abff25af8dac0cf39da4dfd51b3fb4f1ef0b4e776185d4280fbe8387c2ea778da7bbf2ce288b0bce4d23cbe8d9e87bbd250159044f5adbac78
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Filesize
65KB
MD5901881b087d6365521baf1cfc3a09c9a
SHA16fd3d0b471fe6230b9a2c99725195805e51417bc
SHA256a56298f6eadb8b03e394d8e7d4ad6898a9b88c02ae4eb6a08174cad4fa626354
SHA512e1a2e55e2696bed56121b7afaf2ad3046a0787fdd2bc190a2eb6530d59936abf1223d0422e0e240eecc0e2958dfaa884f62d3e7ba0404448ea1f6b469a857907
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Filesize
66KB
MD51607096aab919751cceaa294bd07733e
SHA1509472b6b011e202d4ae35df80b8cca44acce924
SHA256c4805aac0fed0f6318244c34a50b5612b55bb36611c8306a8820cf0db9480813
SHA512e05a39d901bf56a9a83400171066891428ed97aabd7b5b3e539b5d29067bbdb312fed4e2e175e684c2f16272333e61fb28069bdbb72da23ce9b9e32f3a18e78e
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Filesize
63KB
MD531939ac5200472a417faf3b6c4504a40
SHA1f467058b6cbde29bca7bf66d3e182abce2a0f5f6
SHA2562918cbdd03bd34774fdf83732c1dd0f6e889d69d00de2afec7e2964d4744af53
SHA51253d20da3fb6a39b6069631dd1d281e8621f9ff562f3e5a6d3c32495e48539d02da737b51dab87fb1f17df444d9d49739c1f7115b2e15211d494c2ce66c5b842e