buer | 63e6f759e7978643e5b7998f737688b8a5c08ad0ce843ba20822c7d9125e4714

General

Target

Private document.docm
Size

2.0MB
MD5

526e3392d7634da433db9ae9dce6a9b6
SHA1

f182af125f4b8b0953ab2755e50dc5a8ba3294c9
SHA256

63e6f759e7978643e5b7998f737688b8a5c08ad0ce843ba20822c7d9125e4714
SHA512

961d2b015376d723023f55659b9c1d3f7bdccf934d73c751cb7acf1fa8685a5e88308c8feb31bc132487d243c060b2fdcd2c176a1d1dd23d0c22339f342aeab1

Score

10^/10

buer loader

Malware Config

Extracted

Family

buer

C2

cembank-api.com

Signatures

Buer
Buer is a new modular loader first seen in August 2019.
loader buer

Process spawned unexpected child process 1 IoCs

This typically indicates the parent process was compromised via an exploit or macro.

description	pid	pid_target	Process	procid_target
Parent C:\Program Files (x86)\Microsoft Office\Office14\WINWORD.EXE is not expected to spawn this process	1672	1904	rundll32.exe	24

Buer Loader 1 IoCs

Detects Buer loader in memory or disk.

resource	yara_rule
behavioral1/memory/632-16-0x0000000040000000-0x000000004000A000-memory.dmp	buer

Executes dropped EXE 2 IoCs

pid	Process
268	Office_WorkForWestBank.exe
632	Office_WorkForWestBank.exe

Loads dropped DLL 2 IoCs

pid	Process
1672	rundll32.exe
268	Office_WorkForWestBank.exe

Suspicious use of SetThreadContext 1 IoCs

description	pid	Process	procid_target
PID 268 set thread context of 632	268	Office_WorkForWestBank.exe	33

Drops file in Windows directory 1 IoCs

description	ioc	Process
File opened for modification	C:\Windows\Debug\WIA\wiatrace.log	WINWORD.EXE

Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s). Likely ransomware behaviour.

System Information Discovery
T1082

NSIS installer 8 IoCs

installer

resource	yara_rule
behavioral1/files/0x00030000000130e7-9.dat	nsis_installer_1
behavioral1/files/0x00030000000130e7-9.dat	nsis_installer_2
behavioral1/files/0x00030000000130e7-11.dat	nsis_installer_1
behavioral1/files/0x00030000000130e7-11.dat	nsis_installer_2
behavioral1/files/0x00030000000130e7-8.dat	nsis_installer_1
behavioral1/files/0x00030000000130e7-8.dat	nsis_installer_2
behavioral1/files/0x00030000000130e7-15.dat	nsis_installer_1
behavioral1/files/0x00030000000130e7-15.dat	nsis_installer_2

Office loads VBA resources, possible macro or embedded object present

Modifies Internet Explorer settings 1 TTPs 9 IoCs

adware spyware

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\Toolbar\ShowDiscussionButton = "Yes"	WINWORD.EXE
Key created	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\MenuExt\Se&nd to OneNote	WINWORD.EXE
Set value (int)	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\MenuExt\Se&nd to OneNote\Contexts = "55"	WINWORD.EXE
Set value (str)	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\MenuExt\E&xport to Microsoft Excel\ = "res://C:\\PROGRA~2\\MICROS~1\\Office14\\EXCEL.EXE/3000"	WINWORD.EXE
Key created	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\Toolbar	WINWORD.EXE
Set value (str)	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\MenuExt\Se&nd to OneNote\ = "res://C:\\PROGRA~2\\MICROS~1\\Office14\\ONBttnIE.dll/105"	WINWORD.EXE
Key created	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\MenuExt\E&xport to Microsoft Excel	WINWORD.EXE
Set value (int)	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\MenuExt\E&xport to Microsoft Excel\Contexts = "1"	WINWORD.EXE
Key created	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\MenuExt	WINWORD.EXE

Suspicious behavior: AddClipboardFormatListener 1 IoCs

pid	Process
1904	WINWORD.EXE

Suspicious behavior: MapViewOfSection 1 IoCs

pid	Process
268	Office_WorkForWestBank.exe

Suspicious use of SetWindowsHookEx 2 IoCs

pid	Process
1904	WINWORD.EXE
1904	WINWORD.EXE

Suspicious use of WriteProcessMemory 16 IoCs

description	pid	Process	procid_target
PID 1904 wrote to memory of 1672	1904	WINWORD.EXE	30
PID 1904 wrote to memory of 1672	1904	WINWORD.EXE	30
PID 1904 wrote to memory of 1672	1904	WINWORD.EXE	30
PID 1904 wrote to memory of 1672	1904	WINWORD.EXE	30
PID 1904 wrote to memory of 1672	1904	WINWORD.EXE	30
PID 1904 wrote to memory of 1672	1904	WINWORD.EXE	30
PID 1904 wrote to memory of 1672	1904	WINWORD.EXE	30
PID 1672 wrote to memory of 268	1672	rundll32.exe	31
PID 1672 wrote to memory of 268	1672	rundll32.exe	31
PID 1672 wrote to memory of 268	1672	rundll32.exe	31
PID 1672 wrote to memory of 268	1672	rundll32.exe	31
PID 268 wrote to memory of 632	268	Office_WorkForWestBank.exe	33
PID 268 wrote to memory of 632	268	Office_WorkForWestBank.exe	33
PID 268 wrote to memory of 632	268	Office_WorkForWestBank.exe	33
PID 268 wrote to memory of 632	268	Office_WorkForWestBank.exe	33
PID 268 wrote to memory of 632	268	Office_WorkForWestBank.exe	33

C:\Program Files (x86)\Microsoft Office\Office14\WINWORD.EXE
"C:\Program Files (x86)\Microsoft Office\Office14\WINWORD.EXE" /n "C:\Users\Admin\AppData\Local\Temp\Private document.docm"
1⤵
- Drops file in Windows directory
- Modifies Internet Explorer settings
- Suspicious behavior: AddClipboardFormatListener
- Suspicious use of SetWindowsHookEx
- Suspicious use of WriteProcessMemory
PID:1904
- C:\Windows\SysWOW64\rundll32.exe
  rundll32 advpack.dll, RegisterOCX C:\ProgramData\Office_WorkForWestBank.exe
  2⤵
  - Process spawned unexpected child process
  - Loads dropped DLL
  - Suspicious use of WriteProcessMemory
  PID:1672
- - C:\ProgramData\Office_WorkForWestBank.exe
    C:\ProgramData\Office_WorkForWestBank.exe /RegServer
    3⤵
    - Executes dropped EXE
    - Loads dropped DLL
    - Suspicious use of SetThreadContext
    - Suspicious behavior: MapViewOfSection
    - Suspicious use of WriteProcessMemory
    PID:268
  - - C:\ProgramData\Office_WorkForWestBank.exe
      C:\ProgramData\Office_WorkForWestBank.exe /RegServer
      4⤵
      Executes dropped EXE
      PID:632

Network

MITRE ATT&CK Enterprise v6

Initial Access

Execution

Persistence

Privilege Escalation

Defense Evasion

Modify Registry

1

T1112

Credential Access

Discovery

System Information Discovery

1

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Replay Monitor

Loading Replay Monitor...

Downloads

memory/632-16-0x0000000040000000-0x000000004000A000-memory.dmp

Filesize
40KB

Download
memory/1672-7-0x00000000766F1000-0x00000000766F3000-memory.dmp

Filesize
8KB

Download
memory/1904-2-0x00000000728E1000-0x00000000728E4000-memory.dmp

Filesize
12KB

Download
memory/1904-5-0x0000000000650000-0x0000000000651000-memory.dmp

Filesize
4KB

Download
memory/1904-4-0x000000005FFF0000-0x0000000060000000-memory.dmp

Filesize
64KB

Download
memory/1904-3-0x0000000070361000-0x0000000070363000-memory.dmp

Filesize
8KB

Download

Analysis

Sharing