buer | 48169d26f0752a5bb08334a4a41bbd2cc890c326fc0115e3b9ac1db6f9741930

General

Target

48169d26f0752a5bb08334a4a41bbd2cc890c326fc0115e3b9ac1db6f9741930.exe
Size

253KB
MD5

5c86e45799654b4ff55e5f84d4a483e2
SHA1

f840b9b62d1b4c8072883876edf03a2274323a7f
SHA256

48169d26f0752a5bb08334a4a41bbd2cc890c326fc0115e3b9ac1db6f9741930
SHA512

c91c1240567eeace40e1cc37580b729fe43040b370b13a7a247c0c706478290855745397cb0f8ba6e79a58b552f66ea2e75fc8f3dd494359776d2e7b978164cf

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-1-5-21-3751123196-3323558407-1869646069-1000\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\ProgramData\\ErrorResponder\\errorResponder.exe\""	errorResponder.exe

Buer Loader 5 IoCs

Detects Buer loader in memory or disk.

loader

resource	yara_rule
behavioral2/memory/4224-131-0x0000000000480000-0x000000000048A000-memory.dmp	buer
behavioral2/memory/4224-132-0x0000000040000000-0x00000000442DB000-memory.dmp	buer
behavioral2/memory/4224-134-0x0000000040000000-0x00000000442DB000-memory.dmp	buer
behavioral2/memory/3692-139-0x0000000040000000-0x00000000442DB000-memory.dmp	buer
behavioral2/memory/4224-140-0x0000000040000000-0x00000000442DB000-memory.dmp	buer

Executes dropped EXE 1 IoCs

pid	Process
3692	errorResponder.exe

Program crash 3 IoCs

pid	pid_target	Process	procid_target
4404	4224	WerFault.exe	79
1528	4224	WerFault.exe	79
3144	2892	WerFault.exe	93

Suspicious behavior: EnumeratesProcesses 2 IoCs

pid	Process
3692	errorResponder.exe
3692	errorResponder.exe

Suspicious use of WriteProcessMemory 13 IoCs

description	pid	Process	procid_target
PID 4224 wrote to memory of 3692	4224	48169d26f0752a5bb08334a4a41bbd2cc890c326fc0115e3b9ac1db6f9741930.exe	87
PID 4224 wrote to memory of 3692	4224	48169d26f0752a5bb08334a4a41bbd2cc890c326fc0115e3b9ac1db6f9741930.exe	87
PID 4224 wrote to memory of 3692	4224	48169d26f0752a5bb08334a4a41bbd2cc890c326fc0115e3b9ac1db6f9741930.exe	87
PID 3692 wrote to memory of 2892	3692	errorResponder.exe	93
PID 3692 wrote to memory of 2892	3692	errorResponder.exe	93
PID 3692 wrote to memory of 2892	3692	errorResponder.exe	93
PID 3692 wrote to memory of 2892	3692	errorResponder.exe	93
PID 3692 wrote to memory of 2892	3692	errorResponder.exe	93
PID 3692 wrote to memory of 2892	3692	errorResponder.exe	93
PID 3692 wrote to memory of 2892	3692	errorResponder.exe	93
PID 3692 wrote to memory of 2892	3692	errorResponder.exe	93
PID 3692 wrote to memory of 2892	3692	errorResponder.exe	93
PID 3692 wrote to memory of 2892	3692	errorResponder.exe	93

C:\Users\Admin\AppData\Local\Temp\48169d26f0752a5bb08334a4a41bbd2cc890c326fc0115e3b9ac1db6f9741930.exe
"C:\Users\Admin\AppData\Local\Temp\48169d26f0752a5bb08334a4a41bbd2cc890c326fc0115e3b9ac1db6f9741930.exe"
1⤵
- Suspicious use of WriteProcessMemory
PID:4224
- C:\ProgramData\ErrorResponder\errorResponder.exe
  C:\ProgramData\ErrorResponder\errorResponder.exe "C:\Users\Admin\AppData\Local\Temp\48169d26f0752a5bb08334a4a41bbd2cc890c326fc0115e3b9ac1db6f9741930.exe" ensgJJ
  2⤵
  - Modifies WinLogon for persistence
  - Executes dropped EXE
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of WriteProcessMemory
  PID:3692
- - C:\Windows\SysWOW64\secinit.exe
    C:\ProgramData\ErrorResponder\errorResponder.exe
    3⤵
    PID:2892
  - - C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 2892 -s 272
      4⤵
      Program crash
      PID:3144
- C:\Windows\SysWOW64\WerFault.exe
  C:\Windows\SysWOW64\WerFault.exe -u -p 4224 -s 440
  2⤵
  - Program crash
  PID:4404
- C:\Windows\SysWOW64\WerFault.exe
  C:\Windows\SysWOW64\WerFault.exe -u -p 4224 -s 472
  2⤵
  - Program crash
  PID:1528

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 412 -p 4224 -ip 4224
1⤵
PID:2020

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 492 -p 4224 -ip 4224
1⤵
PID:4356

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 488 -p 2892 -ip 2892
1⤵
PID:3536

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

Loading Replay Monitor...

Downloads

C:\ProgramData\ErrorResponder\errorResponder.exe

Filesize
253KB

MD5
5c86e45799654b4ff55e5f84d4a483e2

SHA1
f840b9b62d1b4c8072883876edf03a2274323a7f

SHA256
48169d26f0752a5bb08334a4a41bbd2cc890c326fc0115e3b9ac1db6f9741930

SHA512
c91c1240567eeace40e1cc37580b729fe43040b370b13a7a247c0c706478290855745397cb0f8ba6e79a58b552f66ea2e75fc8f3dd494359776d2e7b978164cf

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

Filesize
253KB

MD5
5c86e45799654b4ff55e5f84d4a483e2

SHA1
f840b9b62d1b4c8072883876edf03a2274323a7f

SHA256
48169d26f0752a5bb08334a4a41bbd2cc890c326fc0115e3b9ac1db6f9741930

SHA512
c91c1240567eeace40e1cc37580b729fe43040b370b13a7a247c0c706478290855745397cb0f8ba6e79a58b552f66ea2e75fc8f3dd494359776d2e7b978164cf

Download Submit
memory/2892-142-0x0000000000C00000-0x0000000004EDB000-memory.dmp

Filesize
66.9MB

Download
memory/3692-139-0x0000000040000000-0x00000000442DB000-memory.dmp

Filesize
66.9MB

Download
memory/3692-138-0x000000000079D000-0x00000000007A4000-memory.dmp

Filesize
28KB

Download
memory/4224-134-0x0000000040000000-0x00000000442DB000-memory.dmp

Filesize
66.9MB

Download
memory/4224-133-0x00000000004AE000-0x00000000004B6000-memory.dmp

Filesize
32KB

Download
memory/4224-130-0x00000000004AE000-0x00000000004B6000-memory.dmp

Filesize
32KB

Download
memory/4224-140-0x0000000040000000-0x00000000442DB000-memory.dmp

Filesize
66.9MB

Download
memory/4224-132-0x0000000040000000-0x00000000442DB000-memory.dmp

Filesize
66.9MB

Download
memory/4224-131-0x0000000000480000-0x000000000048A000-memory.dmp

Filesize
40KB

Download

Analysis

Sharing