buer | e173a639506cfac3f65723d711ad072d18b95f2776581d43407e1ffb6bec441f

General

Target

e173a639506cfac3f65723d711ad072d18b95f2776581d43407e1ffb6bec441f.exe
Size

236KB
MD5

f539613bb8aa110f64481c22d073f510
SHA1

c961c5aec12d17d0e6427bb2886619d604947c9a
SHA256

e173a639506cfac3f65723d711ad072d18b95f2776581d43407e1ffb6bec441f
SHA512

dba51c39a1d9f8cfe9d2a9b1cd9b06cb25f8bc60d3cae43105bb32cee0e7ff96960bd2438d4ee6e641a1416c05a5c67036696e195bb9f1cf17e49ebf158fc276

Score

10^/10

buer loader persistence

Malware Config

Extracted

Family

buer

C2

https://gstatiknetiplist.cc/

https://gstatiknetiplist.com/

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-1-5-21-2277218442-1199762539-2004043321-1000\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\ProgramData\\ErrorResponder\\responder.exe\""	responder.exe

Buer Loader 3 IoCs

Detects Buer loader in memory or disk.

loader

resource	yara_rule
behavioral1/memory/936-57-0x00000000003A0000-0x00000000003AA000-memory.dmp	buer
behavioral1/memory/936-58-0x0000000040000000-0x0000000042824000-memory.dmp	buer
behavioral1/memory/2040-68-0x0000000040000000-0x0000000042824000-memory.dmp	buer

Executes dropped EXE 1 IoCs

pid	Process
2040	responder.exe

Deletes itself 1 IoCs

pid	Process
2040	responder.exe

Loads dropped DLL 2 IoCs

pid	Process
936	e173a639506cfac3f65723d711ad072d18b95f2776581d43407e1ffb6bec441f.exe
936	e173a639506cfac3f65723d711ad072d18b95f2776581d43407e1ffb6bec441f.exe

Enumerates connected drives 3 TTPs 20 IoCs

Attempts to read the root path of hard drives other than the default C: drive.

Query Registry

T1012

Peripheral Device Discovery

T1120

System Information Discovery

T1082

description	ioc	Process
File opened (read-only)	\??\R:	responder.exe
File opened (read-only)	\??\T:	responder.exe
File opened (read-only)	\??\G:	responder.exe
File opened (read-only)	\??\O:	responder.exe
File opened (read-only)	\??\H:	responder.exe
File opened (read-only)	\??\N:	responder.exe
File opened (read-only)	\??\Q:	responder.exe
File opened (read-only)	\??\S:	responder.exe
File opened (read-only)	\??\V:	responder.exe
File opened (read-only)	\??\E:	responder.exe
File opened (read-only)	\??\F:	responder.exe
File opened (read-only)	\??\M:	responder.exe
File opened (read-only)	\??\P:	responder.exe
File opened (read-only)	\??\U:	responder.exe
File opened (read-only)	\??\I:	responder.exe
File opened (read-only)	\??\L:	responder.exe
File opened (read-only)	\??\J:	responder.exe
File opened (read-only)	\??\K:	responder.exe
File opened (read-only)	\??\A:	responder.exe
File opened (read-only)	\??\B:	responder.exe

Program crash 1 IoCs

pid	pid_target	Process	procid_target
660	1308	WerFault.exe	29

Suspicious use of WriteProcessMemory 19 IoCs

description	pid	Process	procid_target
PID 936 wrote to memory of 2040	936	e173a639506cfac3f65723d711ad072d18b95f2776581d43407e1ffb6bec441f.exe	28
PID 936 wrote to memory of 2040	936	e173a639506cfac3f65723d711ad072d18b95f2776581d43407e1ffb6bec441f.exe	28
PID 936 wrote to memory of 2040	936	e173a639506cfac3f65723d711ad072d18b95f2776581d43407e1ffb6bec441f.exe	28
PID 936 wrote to memory of 2040	936	e173a639506cfac3f65723d711ad072d18b95f2776581d43407e1ffb6bec441f.exe	28
PID 2040 wrote to memory of 1308	2040	responder.exe	29
PID 2040 wrote to memory of 1308	2040	responder.exe	29
PID 2040 wrote to memory of 1308	2040	responder.exe	29
PID 2040 wrote to memory of 1308	2040	responder.exe	29
PID 2040 wrote to memory of 1308	2040	responder.exe	29
PID 2040 wrote to memory of 1308	2040	responder.exe	29
PID 2040 wrote to memory of 1308	2040	responder.exe	29
PID 2040 wrote to memory of 1308	2040	responder.exe	29
PID 2040 wrote to memory of 1308	2040	responder.exe	29
PID 2040 wrote to memory of 1308	2040	responder.exe	29
PID 2040 wrote to memory of 1308	2040	responder.exe	29
PID 1308 wrote to memory of 660	1308	secinit.exe	30
PID 1308 wrote to memory of 660	1308	secinit.exe	30
PID 1308 wrote to memory of 660	1308	secinit.exe	30
PID 1308 wrote to memory of 660	1308	secinit.exe	30

C:\Users\Admin\AppData\Local\Temp\e173a639506cfac3f65723d711ad072d18b95f2776581d43407e1ffb6bec441f.exe
"C:\Users\Admin\AppData\Local\Temp\e173a639506cfac3f65723d711ad072d18b95f2776581d43407e1ffb6bec441f.exe"
1⤵
- Loads dropped DLL
- Suspicious use of WriteProcessMemory
PID:936
- C:\ProgramData\ErrorResponder\responder.exe
  C:\ProgramData\ErrorResponder\responder.exe "C:\Users\Admin\AppData\Local\Temp\e173a639506cfac3f65723d711ad072d18b95f2776581d43407e1ffb6bec441f.exe" ensgJJ
  2⤵
  - Modifies WinLogon for persistence
  - Executes dropped EXE
  - Deletes itself
  - Enumerates connected drives
  - Suspicious use of WriteProcessMemory
  PID:2040
- - C:\Windows\SysWOW64\secinit.exe
    C:\ProgramData\ErrorResponder\responder.exe
    3⤵
    - Suspicious use of WriteProcessMemory
    PID:1308
  - - C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 1308 -s 136
      4⤵
      Program crash
      PID:660

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

Peripheral Device Discovery

Query Registry

System Information Discovery

1

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Replay Monitor

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Downloads

C:\ProgramData\ErrorResponder\responder.exe

Filesize
236KB

MD5
f539613bb8aa110f64481c22d073f510

SHA1
c961c5aec12d17d0e6427bb2886619d604947c9a

SHA256
e173a639506cfac3f65723d711ad072d18b95f2776581d43407e1ffb6bec441f

SHA512
dba51c39a1d9f8cfe9d2a9b1cd9b06cb25f8bc60d3cae43105bb32cee0e7ff96960bd2438d4ee6e641a1416c05a5c67036696e195bb9f1cf17e49ebf158fc276

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

Filesize
236KB

MD5
f539613bb8aa110f64481c22d073f510

SHA1
c961c5aec12d17d0e6427bb2886619d604947c9a

SHA256
e173a639506cfac3f65723d711ad072d18b95f2776581d43407e1ffb6bec441f

SHA512
dba51c39a1d9f8cfe9d2a9b1cd9b06cb25f8bc60d3cae43105bb32cee0e7ff96960bd2438d4ee6e641a1416c05a5c67036696e195bb9f1cf17e49ebf158fc276

Download Submit
\ProgramData\ErrorResponder\responder.exe

Filesize
236KB

MD5
f539613bb8aa110f64481c22d073f510

SHA1
c961c5aec12d17d0e6427bb2886619d604947c9a

SHA256
e173a639506cfac3f65723d711ad072d18b95f2776581d43407e1ffb6bec441f

SHA512
dba51c39a1d9f8cfe9d2a9b1cd9b06cb25f8bc60d3cae43105bb32cee0e7ff96960bd2438d4ee6e641a1416c05a5c67036696e195bb9f1cf17e49ebf158fc276

Download Submit
\ProgramData\ErrorResponder\responder.exe

Filesize
236KB

MD5
f539613bb8aa110f64481c22d073f510

SHA1
c961c5aec12d17d0e6427bb2886619d604947c9a

SHA256
e173a639506cfac3f65723d711ad072d18b95f2776581d43407e1ffb6bec441f

SHA512
dba51c39a1d9f8cfe9d2a9b1cd9b06cb25f8bc60d3cae43105bb32cee0e7ff96960bd2438d4ee6e641a1416c05a5c67036696e195bb9f1cf17e49ebf158fc276

Download Submit
memory/936-55-0x00000000750C1000-0x00000000750C3000-memory.dmp

Filesize
8KB

Download
memory/936-56-0x0000000000230000-0x0000000000330000-memory.dmp

Filesize
1024KB

Download
memory/936-57-0x00000000003A0000-0x00000000003AA000-memory.dmp

Filesize
40KB

Download
memory/936-58-0x0000000040000000-0x0000000042824000-memory.dmp

Filesize
40.1MB

Download
memory/936-59-0x0000000000230000-0x0000000000330000-memory.dmp

Filesize
1024KB

Download
memory/1308-73-0x0000000000BB0000-0x00000000033D4000-memory.dmp

Filesize
40.1MB

Download
memory/1308-70-0x0000000000BB0000-0x00000000033D4000-memory.dmp

Filesize
40.1MB

Download
memory/1308-71-0x0000000000BB0000-0x00000000033D4000-memory.dmp

Filesize
40.1MB

Download
memory/1308-75-0x0000000000BB0000-0x00000000033D4000-memory.dmp

Filesize
40.1MB

Download
memory/1308-77-0x0000000000BB0000-0x00000000033D4000-memory.dmp

Filesize
40.1MB

Download
memory/1308-79-0x0000000000080000-0x0000000000081000-memory.dmp

Filesize
4KB

Download
memory/2040-68-0x0000000040000000-0x0000000042824000-memory.dmp

Filesize
40.1MB

Download
memory/2040-69-0x0000000000230000-0x0000000000330000-memory.dmp

Filesize
1024KB

Download
memory/2040-67-0x0000000000230000-0x0000000000330000-memory.dmp

Filesize
1024KB

Download

Analysis

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