41d0974cbdef4ea3f95857128c668217b42510a911b620909b430ca9575ebd78

General

Target
jaffacakes118_Trojan-Downloader.Win32.Small.bsw.exe
Size 36KB
Sample261006-p86tgazvbw
SHA256 41d0974cbdef4ea3f95857128c668217b42510a911b620909b430ca9575ebd78
MD5 846ea7fee0162e056fab3828e1dbefc0
SHA1 ac0284458e84832e0c9f666c6d381487a1925236
SHA512 d29018fa43b919de1f730e15d608ccd34e142f9b1102a87a4ea3dc039ddf4a185d8398b51ded89e923a036d7e50a1838e19df687773b0d8aebbae5a913c8937d
SSDEEP 768:r5a81vWHW4mCVrTdYHNocTd5kG2f298+PxPha5:r51hWZDV9YtVP2fGv3
TLSH
T164F2E15BEED9C83EE1CA75F152358207FA3C1821B133466F561A4C9A7DD2831A83D793
MD5 SHA1 SHA512 SSDEEP TLSH

Score

10^/10

defense_evasion discovery persistence

Malware Config

Signatures

Modifies WinLogon for persistence 2 TTPs 1 IoCs

persistence

Winlogon Helper DLL

T1547.004

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\Userinit = "C:\\WINDOWS\\Help\\csrsss.exe,"	jaffacakes118_Trojan-Downloader.Win32.Small.bsw.exe

Sets file to hidden 1 TTPs 2 IoCs

Modifies file attributes to stop it showing in Explorer etc.

defense_evasion

Hidden Files and Directories

T1564.001

pid	Process
2132	attrib.exe
3668	attrib.exe

Adds Run key to start application 2 TTPs 1 IoCs

persistence

Registry Run Keys / Startup Folder

T1547.001

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Run\Bug = "C:\\Windows\\system32\\csrsss.exe"	jaffacakes118_Trojan-Downloader.Win32.Small.bsw.exe

Drops file in System32 directory 3 IoCs

description	ioc	Process
File created	C:\Windows\SysWOW64\csrsss.exe	jaffacakes118_Trojan-Downloader.Win32.Small.bsw.exe
File opened for modification	C:\Windows\SysWOW64\csrsss.exe	attrib.exe
File opened for modification	C:\Windows\SysWOW64\csrsss.exe	attrib.exe

Drops file in Windows directory 3 IoCs

description	ioc	Process
File opened for modification	C:\WINDOWS\Help\csrsss.exe	attrib.exe
File opened for modification	C:\WINDOWS\Help\csrsss.exe	attrib.exe
File created	C:\WINDOWS\Help\csrsss.exe	jaffacakes118_Trojan-Downloader.Win32.Small.bsw.exe

Reads the TCP/IP host and domain name from the registry 1 TTPs 2 IoCs

The configured hostname and DNS domain identify the machine and are commonly collected to profile a host before it reports in.

discovery

System Network Configuration Discovery

T1016

description	ioc	Process
Key value queried	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters\Hostname	jaffacakes118_Trojan-Downloader.Win32.Small.bsw.exe
Key value queried	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters\Domain	jaffacakes118_Trojan-Downloader.Win32.Small.bsw.exe

System Location Discovery: System Language Discovery 1 TTPs 5 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

description	ioc	Process
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	jaffacakes118_Trojan-Downloader.Win32.Small.bsw.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	attrib.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	attrib.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	attrib.exe
Key opened	\REGISTRY\MACHINE\SYSTEM\ControlSet001\Control\NLS\Language	attrib.exe

Suspicious use of WriteProcessMemory 4 IoCs

description	pid	Process	procid_target
PID 4640 wrote to memory of 2072	4640	jaffacakes118_Trojan-Downloader.Win32.Small.bsw.exe	89
PID 4640 wrote to memory of 3668	4640	jaffacakes118_Trojan-Downloader.Win32.Small.bsw.exe	90
PID 4640 wrote to memory of 2100	4640	jaffacakes118_Trojan-Downloader.Win32.Small.bsw.exe	91
PID 4640 wrote to memory of 2132	4640	jaffacakes118_Trojan-Downloader.Win32.Small.bsw.exe	92

Views/modifies file attributes 1 TTPs 4 IoCs

defense_evasion

Hidden Files and Directories

T1564.001

pid	Process
2072	attrib.exe
3668	attrib.exe
2132	attrib.exe
2100	attrib.exe

C:\Users\Admin\AppData\Local\Temp\jaffacakes118_Trojan-Downloader.Win32.Small.bsw.exe
"C:\Users\Admin\AppData\Local\Temp\jaffacakes118_Trojan-Downloader.Win32.Small.bsw.exe"
1⤵
- Modifies WinLogon for persistence
- Adds Run key to start application
- Drops file in System32 directory
- Drops file in Windows directory
- Reads the TCP/IP host and domain name from the registry
- System Location Discovery: System Language Discovery
- Suspicious use of WriteProcessMemory
PID:4640
- C:\Windows\SysWOW64\attrib.exe
  attrib C:\Windows\system32\csrsss.exe -r -s -h
  2⤵
  - Drops file in System32 directory
  - System Location Discovery: System Language Discovery
  - Views/modifies file attributes
  PID:2072
- C:\Windows\SysWOW64\attrib.exe
  attrib C:\Windows\system32\csrsss.exe +r +s +h
  2⤵
  - Sets file to hidden
  - Drops file in System32 directory
  - System Location Discovery: System Language Discovery
  - Views/modifies file attributes
  PID:3668
- C:\Windows\SysWOW64\attrib.exe
  attrib C:\WINDOWS\Help\csrsss.exe -r -s -h
  2⤵
  - Drops file in Windows directory
  - System Location Discovery: System Language Discovery
  - Views/modifies file attributes
  PID:2100
- C:\Windows\SysWOW64\attrib.exe
  attrib C:\WINDOWS\Help\csrsss.exe +r +s +h
  2⤵
  - Sets file to hidden
  - Drops file in Windows directory
  - System Location Discovery: System Language Discovery
  - Views/modifies file attributes
  PID:2132