vobfus | 5347bc0875f7cf043efd17d2b930ce61ed76a9b5274af58257b4dbf8e85b62ac

Windows Service

T1543.003

description	ioc	Process
Key created	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List	77c00bd37b3a0208043de3fb65e2e131.exe

Vobfus
A widespread worm which spreads via network drives and removable media.
worm vobfus

Adds policy Run key to start application 2 TTPs 4 IoCs

persistence

Registry Run Keys / Startup Folder

Modify Registry

description	ioc	Process
Key created	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\run	77c00bd37b3a0208043de3fb65e2e131.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\run\DE8IC59V8SN8W = "C:\\Users\\Admin\\AppData\\Roaming\\9VPF3974KG.exe"	77c00bd37b3a0208043de3fb65e2e131.exe
Key created	\REGISTRY\USER\S-1-5-21-3818056530-936619650-3554021955-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\run	77c00bd37b3a0208043de3fb65e2e131.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3818056530-936619650-3554021955-1000\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\run\DE8IC59V8SN8W = "C:\\Users\\Admin\\AppData\\Roaming\\9VPF3974KG.exe"	77c00bd37b3a0208043de3fb65e2e131.exe

Drops file in Drivers directory 1 IoCs

description	ioc	Process
File opened for modification	C:\Windows\System32\drivers\etc\hosts	77c00bd37b3a0208043de3fb65e2e131.exe

UPX packed file 8 IoCs

Detects executables packed with UPX/modified UPX open source packer.

upx

resource	yara_rule
behavioral1/memory/1992-0-0x0000000000400000-0x0000000000495000-memory.dmp	upx
behavioral1/memory/1832-4-0x0000000000400000-0x0000000000433000-memory.dmp	upx
behavioral1/memory/1832-9-0x0000000000400000-0x0000000000433000-memory.dmp	upx
behavioral1/memory/1832-8-0x0000000000400000-0x0000000000433000-memory.dmp	upx
behavioral1/memory/1992-7-0x0000000000400000-0x0000000000495000-memory.dmp	upx
behavioral1/memory/1832-14-0x0000000000400000-0x0000000000433000-memory.dmp	upx
behavioral1/files/0x000c000000012327-17.dat	upx
behavioral1/memory/1832-33-0x0000000000400000-0x0000000000433000-memory.dmp	upx

Adds Run key to start application 2 TTPs 2 IoCs

persistence

Registry Run Keys / Startup Folder

Modify Registry

description	ioc	Process
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Run\DE8IC59V8SN8W = "C:\\Users\\Admin\\AppData\\Roaming\\9VPF3974KG.exe"	77c00bd37b3a0208043de3fb65e2e131.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-3818056530-936619650-3554021955-1000\Software\Microsoft\Windows\CurrentVersion\Run\DE8IC59V8SN8W = "C:\\Users\\Admin\\AppData\\Roaming\\9VPF3974KG.exe"	77c00bd37b3a0208043de3fb65e2e131.exe

Suspicious use of SetThreadContext 1 IoCs

description	pid	Process	procid_target
PID 1992 set thread context of 1832	1992	77c00bd37b3a0208043de3fb65e2e131.exe	28

Script User-Agent 2 IoCs

Uses user-agent string associated with script host/environment.

description	flow	ioc
HTTP User-Agent header	3	Mozilla/4.0 (compatible; Win32; WinHttp.WinHttpRequest.5)
HTTP User-Agent header	8	Mozilla/4.0 (compatible; Win32; WinHttp.WinHttpRequest.5)

Suspicious behavior: GetForegroundWindowSpam 1 IoCs

pid	Process
1832	77c00bd37b3a0208043de3fb65e2e131.exe

Suspicious behavior: RenamesItself 1 IoCs

pid	Process
1832	77c00bd37b3a0208043de3fb65e2e131.exe

Suspicious use of SetWindowsHookEx 2 IoCs

pid	Process
1992	77c00bd37b3a0208043de3fb65e2e131.exe
1832	77c00bd37b3a0208043de3fb65e2e131.exe

Suspicious use of WriteProcessMemory 9 IoCs

description	pid	Process	procid_target
PID 1992 wrote to memory of 1832	1992	77c00bd37b3a0208043de3fb65e2e131.exe	28
PID 1992 wrote to memory of 1832	1992	77c00bd37b3a0208043de3fb65e2e131.exe	28
PID 1992 wrote to memory of 1832	1992	77c00bd37b3a0208043de3fb65e2e131.exe	28
PID 1992 wrote to memory of 1832	1992	77c00bd37b3a0208043de3fb65e2e131.exe	28
PID 1992 wrote to memory of 1832	1992	77c00bd37b3a0208043de3fb65e2e131.exe	28
PID 1992 wrote to memory of 1832	1992	77c00bd37b3a0208043de3fb65e2e131.exe	28
PID 1992 wrote to memory of 1832	1992	77c00bd37b3a0208043de3fb65e2e131.exe	28
PID 1992 wrote to memory of 1832	1992	77c00bd37b3a0208043de3fb65e2e131.exe	28
PID 1992 wrote to memory of 1832	1992	77c00bd37b3a0208043de3fb65e2e131.exe	28

C:\Users\Admin\AppData\Local\Temp\77c00bd37b3a0208043de3fb65e2e131.exe
"C:\Users\Admin\AppData\Local\Temp\77c00bd37b3a0208043de3fb65e2e131.exe"
1⤵
- Modifies firewall policy service
- Drops file in Drivers directory
- Suspicious use of SetThreadContext
- Suspicious use of SetWindowsHookEx
- Suspicious use of WriteProcessMemory
PID:1992
- C:\Users\Admin\AppData\Local\Temp\77c00bd37b3a0208043de3fb65e2e131.exe
  C:\Users\Admin\AppData\Local\Temp\77c00bd37b3a0208043de3fb65e2e131.exe
  2⤵
  - Adds policy Run key to start application
  - Adds Run key to start application
  - Suspicious behavior: GetForegroundWindowSpam
  - Suspicious behavior: RenamesItself
  - Suspicious use of SetWindowsHookEx
  PID:1832

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Persistence

Boot or Logon Autostart Execution

T1547

Registry Run Keys / Startup Folder

Create or Modify System Process

T1543

Windows Service

T1543.003

Privilege Escalation

Boot or Logon Autostart Execution

T1547

Registry Run Keys / Startup Folder

Create or Modify System Process

T1543

Windows Service

T1543.003

Defense Evasion

Modify Registry

3