buer | 4e2a2755b00b276e03677a1444df7317bef390529fa774f9999f907cbce73157

General

Target

4e2a2755b00b276e03677a1444df7317bef390529fa774f9999f907cbce73157.exe
Size

252KB
MD5

91b6202963740e3e9649a14e6a129533
SHA1

16e35c52fc3ac675eadd7c12a13cbc6419c4a0c1
SHA256

4e2a2755b00b276e03677a1444df7317bef390529fa774f9999f907cbce73157
SHA512

c7c71805a32d8d951b7cb60aa0a722995e3abc0d50107688953bf0c2df06a314b150bebdb3208c8bdb6b60d654c16ff3dcfe03fab34d6adfbb62f6abfdc23f80

Score

10^/10

buer loader persistence

Malware Config

Extracted

Family

buer

C2

https://95.217.81.68/

http://95.217.81.68:8080/

Signatures

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

Modifies WinLogon for persistence 2 TTPs 1 IoCs

persistence

Winlogon Helper DLL

T1004

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\USER\S-1-5-21-1819626980-2277161760-1023733287-1000\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\ProgramData\\ErrorResponder\\errorResponder.exe\""	errorResponder.exe

Buer Loader 3 IoCs

Detects Buer loader in memory or disk.

loader

resource	yara_rule
behavioral1/memory/1236-56-0x0000000000220000-0x000000000022A000-memory.dmp	buer
behavioral1/memory/1236-57-0x0000000040000000-0x00000000442DB000-memory.dmp	buer
behavioral1/memory/1256-66-0x0000000040000000-0x00000000442DB000-memory.dmp	buer

Executes dropped EXE 1 IoCs

pid	Process
1256	errorResponder.exe

Deletes itself 1 IoCs

pid	Process
1256	errorResponder.exe

Loads dropped DLL 2 IoCs

pid	Process
1236	4e2a2755b00b276e03677a1444df7317bef390529fa774f9999f907cbce73157.exe
1236	4e2a2755b00b276e03677a1444df7317bef390529fa774f9999f907cbce73157.exe

Program crash 1 IoCs

pid	pid_target	Process	procid_target
520	1976	WerFault.exe	28

Suspicious behavior: EnumeratesProcesses 1 IoCs

pid	Process
1256	errorResponder.exe

Suspicious use of WriteProcessMemory 19 IoCs

description	pid	Process	procid_target
PID 1236 wrote to memory of 1256	1236	4e2a2755b00b276e03677a1444df7317bef390529fa774f9999f907cbce73157.exe	27
PID 1236 wrote to memory of 1256	1236	4e2a2755b00b276e03677a1444df7317bef390529fa774f9999f907cbce73157.exe	27
PID 1236 wrote to memory of 1256	1236	4e2a2755b00b276e03677a1444df7317bef390529fa774f9999f907cbce73157.exe	27
PID 1236 wrote to memory of 1256	1236	4e2a2755b00b276e03677a1444df7317bef390529fa774f9999f907cbce73157.exe	27
PID 1256 wrote to memory of 1976	1256	errorResponder.exe	28
PID 1256 wrote to memory of 1976	1256	errorResponder.exe	28
PID 1256 wrote to memory of 1976	1256	errorResponder.exe	28
PID 1256 wrote to memory of 1976	1256	errorResponder.exe	28
PID 1256 wrote to memory of 1976	1256	errorResponder.exe	28
PID 1256 wrote to memory of 1976	1256	errorResponder.exe	28
PID 1256 wrote to memory of 1976	1256	errorResponder.exe	28
PID 1256 wrote to memory of 1976	1256	errorResponder.exe	28
PID 1256 wrote to memory of 1976	1256	errorResponder.exe	28
PID 1256 wrote to memory of 1976	1256	errorResponder.exe	28
PID 1256 wrote to memory of 1976	1256	errorResponder.exe	28
PID 1976 wrote to memory of 520	1976	secinit.exe	29
PID 1976 wrote to memory of 520	1976	secinit.exe	29
PID 1976 wrote to memory of 520	1976	secinit.exe	29
PID 1976 wrote to memory of 520	1976	secinit.exe	29

C:\Users\Admin\AppData\Local\Temp\4e2a2755b00b276e03677a1444df7317bef390529fa774f9999f907cbce73157.exe
"C:\Users\Admin\AppData\Local\Temp\4e2a2755b00b276e03677a1444df7317bef390529fa774f9999f907cbce73157.exe"
1⤵
- Loads dropped DLL
- Suspicious use of WriteProcessMemory
PID:1236
- C:\ProgramData\ErrorResponder\errorResponder.exe
  C:\ProgramData\ErrorResponder\errorResponder.exe "C:\Users\Admin\AppData\Local\Temp\4e2a2755b00b276e03677a1444df7317bef390529fa774f9999f907cbce73157.exe" ensgJJ
  2⤵
  - Modifies WinLogon for persistence
  - Executes dropped EXE
  - Deletes itself
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of WriteProcessMemory
  PID:1256
- - C:\Windows\SysWOW64\secinit.exe
    C:\ProgramData\ErrorResponder\errorResponder.exe
    3⤵
    - Suspicious use of WriteProcessMemory
    PID:1976
  - - C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 1976 -s 136
      4⤵
      Program crash
      PID:520

Network

MITRE ATT&CK Enterprise v6

Initial Access

Execution

Persistence

Winlogon Helper DLL

1

T1004

Privilege Escalation

Defense Evasion

Modify Registry

1

T1112

Credential Access

Discovery

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Replay Monitor

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Downloads

C:\ProgramData\ErrorResponder\errorResponder.exe

Filesize
252KB

MD5
91b6202963740e3e9649a14e6a129533

SHA1
16e35c52fc3ac675eadd7c12a13cbc6419c4a0c1

SHA256
4e2a2755b00b276e03677a1444df7317bef390529fa774f9999f907cbce73157

SHA512
c7c71805a32d8d951b7cb60aa0a722995e3abc0d50107688953bf0c2df06a314b150bebdb3208c8bdb6b60d654c16ff3dcfe03fab34d6adfbb62f6abfdc23f80

Download Submit
C:\ProgramData\ErrorResponder\errorResponder.exe

Filesize
252KB

MD5
91b6202963740e3e9649a14e6a129533

SHA1
16e35c52fc3ac675eadd7c12a13cbc6419c4a0c1

SHA256
4e2a2755b00b276e03677a1444df7317bef390529fa774f9999f907cbce73157

SHA512
c7c71805a32d8d951b7cb60aa0a722995e3abc0d50107688953bf0c2df06a314b150bebdb3208c8bdb6b60d654c16ff3dcfe03fab34d6adfbb62f6abfdc23f80

Download Submit
\ProgramData\ErrorResponder\errorResponder.exe

Filesize
252KB

MD5
91b6202963740e3e9649a14e6a129533

SHA1
16e35c52fc3ac675eadd7c12a13cbc6419c4a0c1

SHA256
4e2a2755b00b276e03677a1444df7317bef390529fa774f9999f907cbce73157

SHA512
c7c71805a32d8d951b7cb60aa0a722995e3abc0d50107688953bf0c2df06a314b150bebdb3208c8bdb6b60d654c16ff3dcfe03fab34d6adfbb62f6abfdc23f80

Download Submit
\ProgramData\ErrorResponder\errorResponder.exe

Filesize
252KB

MD5
91b6202963740e3e9649a14e6a129533

SHA1
16e35c52fc3ac675eadd7c12a13cbc6419c4a0c1

SHA256
4e2a2755b00b276e03677a1444df7317bef390529fa774f9999f907cbce73157

SHA512
c7c71805a32d8d951b7cb60aa0a722995e3abc0d50107688953bf0c2df06a314b150bebdb3208c8bdb6b60d654c16ff3dcfe03fab34d6adfbb62f6abfdc23f80

Download Submit
memory/1236-54-0x0000000075BD1000-0x0000000075BD3000-memory.dmp

Filesize
8KB

Download
memory/1236-56-0x0000000000220000-0x000000000022A000-memory.dmp

Filesize
40KB

Download
memory/1236-55-0x000000000042B000-0x0000000000433000-memory.dmp

Filesize
32KB

Download
memory/1236-57-0x0000000040000000-0x00000000442DB000-memory.dmp

Filesize
66.9MB

Download
memory/1236-62-0x000000000042B000-0x0000000000433000-memory.dmp

Filesize
32KB

Download
memory/1256-65-0x000000000058B000-0x0000000000593000-memory.dmp

Filesize
32KB

Download
memory/1256-66-0x0000000040000000-0x00000000442DB000-memory.dmp

Filesize
66.9MB

Download
memory/1976-67-0x00000000004A0000-0x000000000477B000-memory.dmp

Filesize
66.9MB

Download
memory/1976-68-0x00000000004A0000-0x000000000477B000-memory.dmp

Filesize
66.9MB

Download
memory/1976-70-0x00000000004A0000-0x000000000477B000-memory.dmp

Filesize
66.9MB

Download
memory/1976-72-0x00000000004A0000-0x000000000477B000-memory.dmp

Filesize
66.9MB

Download
memory/1976-74-0x00000000004A0000-0x000000000477B000-memory.dmp

Filesize
66.9MB

Download
memory/1976-76-0x00000000000C0000-0x00000000000C1000-memory.dmp

Filesize
4KB

Download
memory/1976-80-0x00000000004A0000-0x000000000477B000-memory.dmp

Filesize
66.9MB

Download

Analysis

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