28699bc835568e4b34a52fab3ce19a81d9e4cfa375c4c6225712ba3783c88c53

Processes:

rmass.exe

description	ioc	process
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
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

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.

persistence

Active Setup

T1547.014

Modify Registry

Processes:

rmass.exe

description	ioc	process
Key created	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Active Setup\Installed Components\{48474E42-5742-4757-4847-4E4257424757}	rmass.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Active Setup\Installed Components\{48474E42-5742-4757-4847-4E4257424757}\01234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123 = "a"	rmass.exe
Set value (int)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Active Setup\Installed Components\{48474E42-5742-4757-4847-4E4257424757}\IsInstalled = "1"	rmass.exe
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Active Setup\Installed Components\{48474E42-5742-4757-4847-4E4257424757}\StubPath = "C:\\Windows\\system32\\ahuy.exe"	rmass.exe

Drops file in Drivers directory 1 IoCs

Processes:

rmass.exe

description ioc process

File opened for modification C:\Windows\system32\drivers\etc\hosts rmass.exe

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

persistence

Image File Execution Options Injection

T1546.012

Processes:

rmass.exe

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

Processes:

rmass.exermass.exe

pid process

4812 rmass.exe
4804 rmass.exe

pid	process
4812	rmass.exe
4804	rmass.exe

Windows security modification 2 TTPs 4 IoCs

evasion trojan

Disable or Modify Tools

T1562.001

Modify Registry

Processes:

rmass.exe

description	ioc	process
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
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

Indicator Removal: Clear Persistence 1 TTPs 1 IoCs

remove IFEO.

defense_evasion

Clear Persistence

T1070.009

Processes:

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

persistence

Winlogon Helper DLL

T1547.004

Modify Registry

Processes:

rmass.exe

description	ioc	process
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
Key created	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\{BC84DF00-BC38-9902-8082-6FCBF2D87A0B}	rmass.exe

Drops file in System32 directory 12 IoCs

Processes:

28699bc835568e4b34a52fab3ce19a81d9e4cfa375c4c6225712ba3783c88c53.exermass.exe

description	ioc	process
File opened for modification	C:\Windows\SysWOW64\rmass.exe	28699bc835568e4b34a52fab3ce19a81d9e4cfa375c4c6225712ba3783c88c53.exe
File created	C:\Windows\SysWOW64\rmass.exe	28699bc835568e4b34a52fab3ce19a81d9e4cfa375c4c6225712ba3783c88c53.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\ntdbg.exe	rmass.exe
File created	C:\Windows\SysWOW64\ntdbg.exe	rmass.exe
File opened for modification	C:\Windows\SysWOW64\ahuy.exe	rmass.exe
File created	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\idbg32.exe	rmass.exe
File opened for modification	C:\Windows\SysWOW64\rmass.exe	rmass.exe

UPX packed file 5 IoCs

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

upx

Processes:

resource	yara_rule
behavioral2/memory/2716-0-0x0000000000400000-0x0000000000412000-memory.dmp	upx
C:\Windows\SysWOW64\rmass.exe	upx
behavioral2/memory/2716-7-0x0000000000400000-0x0000000000412000-memory.dmp	upx
behavioral2/memory/4812-41-0x0000000000400000-0x0000000000412000-memory.dmp	upx
behavioral2/memory/4804-46-0x0000000000400000-0x0000000000412000-memory.dmp	upx

Drops file in Program Files directory 3 IoCs

Processes:

rmass.exe

description	ioc	process
File opened for modification	C:\Program Files (x86)\Common Files\System\winrnt.exe	rmass.exe
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

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.

discovery

System Language Discovery

T1614.001

Processes:

28699bc835568e4b34a52fab3ce19a81d9e4cfa375c4c6225712ba3783c88c53.exermass.exermass.exe

description	ioc	process
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	28699bc835568e4b34a52fab3ce19a81d9e4cfa375c4c6225712ba3783c88c53.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

Processes:

rmass.exermass.exe

pid process

4812 rmass.exe
4812 rmass.exe
4812 rmass.exe
4812 rmass.exe
4812 rmass.exe
4812 rmass.exe
4804 rmass.exe
4804 rmass.exe

pid	process
4812	rmass.exe
4812	rmass.exe
4812	rmass.exe
4812	rmass.exe
4812	rmass.exe
4812	rmass.exe
4804	rmass.exe
4804	rmass.exe

Suspicious use of AdjustPrivilegeToken 2 IoCs

Processes:

28699bc835568e4b34a52fab3ce19a81d9e4cfa375c4c6225712ba3783c88c53.exermass.exe

description	pid	process
Token: SeDebugPrivilege	2716	28699bc835568e4b34a52fab3ce19a81d9e4cfa375c4c6225712ba3783c88c53.exe
Token: SeDebugPrivilege	4812	rmass.exe

Suspicious use of WriteProcessMemory 8 IoCs

Processes:

28699bc835568e4b34a52fab3ce19a81d9e4cfa375c4c6225712ba3783c88c53.exermass.exe

description	pid	process	target process
PID 2716 wrote to memory of 4812	2716	28699bc835568e4b34a52fab3ce19a81d9e4cfa375c4c6225712ba3783c88c53.exe	rmass.exe
PID 2716 wrote to memory of 4812	2716	28699bc835568e4b34a52fab3ce19a81d9e4cfa375c4c6225712ba3783c88c53.exe	rmass.exe
PID 2716 wrote to memory of 4812	2716	28699bc835568e4b34a52fab3ce19a81d9e4cfa375c4c6225712ba3783c88c53.exe	rmass.exe
PID 4812 wrote to memory of 4804	4812	rmass.exe	rmass.exe
PID 4812 wrote to memory of 4804	4812	rmass.exe	rmass.exe
PID 4812 wrote to memory of 4804	4812	rmass.exe	rmass.exe
PID 4812 wrote to memory of 620	4812	rmass.exe	winlogon.exe
PID 4812 wrote to memory of 3520	4812	rmass.exe	Explorer.EXE

C:\Windows\system32\winlogon.exe
winlogon.exe
1⤵
PID:620

C:\Windows\Explorer.EXE
C:\Windows\Explorer.EXE
1⤵
PID:3520
- C:\Users\Admin\AppData\Local\Temp\28699bc835568e4b34a52fab3ce19a81d9e4cfa375c4c6225712ba3783c88c53.exe
  "C:\Users\Admin\AppData\Local\Temp\28699bc835568e4b34a52fab3ce19a81d9e4cfa375c4c6225712ba3783c88c53.exe"
  2⤵
  - Drops file in System32 directory
  - System Location Discovery: System Language Discovery
  - Suspicious use of AdjustPrivilegeToken
  - Suspicious use of WriteProcessMemory
  PID:2716
- - 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:4812
  - - C:\Windows\SysWOW64\rmass.exe
      --k33p
      4⤵
      Executes dropped EXE
      System Location Discovery: System Language Discovery
      Suspicious behavior: EnumeratesProcesses
      PID:4804

Network

MITRE ATT&CK Enterprise v15

Reconnaissance

Resource Development

Initial Access

Execution

Persistence

Boot or Logon Autostart Execution

T1547

Active Setup

T1547.014

Winlogon Helper DLL

T1547.004

Event Triggered Execution

T1546

Image File Execution Options Injection

T1546.012

Privilege Escalation

Boot or Logon Autostart Execution

T1547

Active Setup

T1547.014

Winlogon Helper DLL

T1547.004

Event Triggered Execution

T1546

Image File Execution Options Injection

T1546.012

Defense Evasion

Impair Defenses

T1562

Disable or Modify Tools

T1562.001

Indicator Removal

T1070

Clear Persistence

Modify Registry

Credential Access

Discovery

System Location Discovery

T1614

System Language Discovery