buer | e16557266a535dc246ed5de486bf28bc090b4867cf5bb13d97df68a4f1a8884b

General

Target

e16557266a535dc246ed5de486bf28bc090b4867cf5bb13d97df68a4f1a8884b.exe
Size

267KB
MD5

77bb261d5742e63341907e79a570eb2b
SHA1

eba5ee5b28cbe3c65b15430f81e7f105fdbb6468
SHA256

e16557266a535dc246ed5de486bf28bc090b4867cf5bb13d97df68a4f1a8884b
SHA512

b1f6825265a82f7ab8f839d325deaa24cb80144578b69d8f1437aec2d010e5159de4b643cae4d58a6e644910c11b1d23390f4192c60ce83fdfb9281c371217ef

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 4 IoCs

Detects Buer loader in memory or disk.

loader

resource	yara_rule
behavioral1/memory/900-55-0x00000000002A0000-0x00000000002AA000-memory.dmp	buer
behavioral1/memory/900-57-0x0000000040000000-0x0000000040054000-memory.dmp	buer
behavioral1/memory/900-59-0x00000000002A0000-0x00000000002AA000-memory.dmp	buer
behavioral1/memory/1936-68-0x0000000040000000-0x0000000040054000-memory.dmp	buer

Executes dropped EXE 1 IoCs

pid	Process
1936	responder.exe

Deletes itself 1 IoCs

pid	Process
1936	responder.exe

Loads dropped DLL 2 IoCs

pid	Process
900	e16557266a535dc246ed5de486bf28bc090b4867cf5bb13d97df68a4f1a8884b.exe
900	e16557266a535dc246ed5de486bf28bc090b4867cf5bb13d97df68a4f1a8884b.exe

Enumerates connected drives 3 TTPs 24 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)	\??\A:	responder.exe
File opened (read-only)	\??\H:	responder.exe
File opened (read-only)	\??\K:	responder.exe
File opened (read-only)	\??\W:	responder.exe
File opened (read-only)	\??\R:	responder.exe
File opened (read-only)	\??\S:	responder.exe
File opened (read-only)	\??\U:	responder.exe
File opened (read-only)	\??\X:	responder.exe
File opened (read-only)	\??\E:	responder.exe
File opened (read-only)	\??\G:	responder.exe
File opened (read-only)	\??\J:	responder.exe
File opened (read-only)	\??\N:	responder.exe
File opened (read-only)	\??\Y:	responder.exe
File opened (read-only)	\??\F:	responder.exe
File opened (read-only)	\??\I:	responder.exe
File opened (read-only)	\??\P:	responder.exe
File opened (read-only)	\??\T:	responder.exe
File opened (read-only)	\??\Q:	responder.exe
File opened (read-only)	\??\V:	responder.exe
File opened (read-only)	\??\Z:	responder.exe
File opened (read-only)	\??\B:	responder.exe
File opened (read-only)	\??\L:	responder.exe
File opened (read-only)	\??\M:	responder.exe
File opened (read-only)	\??\O:	responder.exe

Program crash 1 IoCs

pid	pid_target	Process	procid_target
1384	1736	WerFault.exe	28

Suspicious behavior: EnumeratesProcesses 1 IoCs

pid	Process
1936	responder.exe

Suspicious use of WriteProcessMemory 19 IoCs

description	pid	Process	procid_target
PID 900 wrote to memory of 1936	900	e16557266a535dc246ed5de486bf28bc090b4867cf5bb13d97df68a4f1a8884b.exe	27
PID 900 wrote to memory of 1936	900	e16557266a535dc246ed5de486bf28bc090b4867cf5bb13d97df68a4f1a8884b.exe	27
PID 900 wrote to memory of 1936	900	e16557266a535dc246ed5de486bf28bc090b4867cf5bb13d97df68a4f1a8884b.exe	27
PID 900 wrote to memory of 1936	900	e16557266a535dc246ed5de486bf28bc090b4867cf5bb13d97df68a4f1a8884b.exe	27
PID 1936 wrote to memory of 1736	1936	responder.exe	28
PID 1936 wrote to memory of 1736	1936	responder.exe	28
PID 1936 wrote to memory of 1736	1936	responder.exe	28
PID 1936 wrote to memory of 1736	1936	responder.exe	28
PID 1936 wrote to memory of 1736	1936	responder.exe	28
PID 1936 wrote to memory of 1736	1936	responder.exe	28
PID 1936 wrote to memory of 1736	1936	responder.exe	28
PID 1936 wrote to memory of 1736	1936	responder.exe	28
PID 1936 wrote to memory of 1736	1936	responder.exe	28
PID 1936 wrote to memory of 1736	1936	responder.exe	28
PID 1936 wrote to memory of 1736	1936	responder.exe	28
PID 1736 wrote to memory of 1384	1736	secinit.exe	29
PID 1736 wrote to memory of 1384	1736	secinit.exe	29
PID 1736 wrote to memory of 1384	1736	secinit.exe	29
PID 1736 wrote to memory of 1384	1736	secinit.exe	29

C:\Users\Admin\AppData\Local\Temp\e16557266a535dc246ed5de486bf28bc090b4867cf5bb13d97df68a4f1a8884b.exe
"C:\Users\Admin\AppData\Local\Temp\e16557266a535dc246ed5de486bf28bc090b4867cf5bb13d97df68a4f1a8884b.exe"
1⤵
- Loads dropped DLL
- Suspicious use of WriteProcessMemory
PID:900
- C:\ProgramData\ErrorResponder\responder.exe
  C:\ProgramData\ErrorResponder\responder.exe "C:\Users\Admin\AppData\Local\Temp\e16557266a535dc246ed5de486bf28bc090b4867cf5bb13d97df68a4f1a8884b.exe" ensgJJ
  2⤵
  - Modifies WinLogon for persistence
  - Executes dropped EXE
  - Deletes itself
  - Enumerates connected drives
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of WriteProcessMemory
  PID:1936
- - C:\Windows\SysWOW64\secinit.exe
    C:\ProgramData\ErrorResponder\responder.exe
    3⤵
    - Suspicious use of WriteProcessMemory
    PID:1736
  - - C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 1736 -s 136
      4⤵
      Program crash
      PID:1384

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
267KB

MD5
77bb261d5742e63341907e79a570eb2b

SHA1
eba5ee5b28cbe3c65b15430f81e7f105fdbb6468

SHA256
e16557266a535dc246ed5de486bf28bc090b4867cf5bb13d97df68a4f1a8884b

SHA512
b1f6825265a82f7ab8f839d325deaa24cb80144578b69d8f1437aec2d010e5159de4b643cae4d58a6e644910c11b1d23390f4192c60ce83fdfb9281c371217ef

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

Filesize
267KB

MD5
77bb261d5742e63341907e79a570eb2b

SHA1
eba5ee5b28cbe3c65b15430f81e7f105fdbb6468

SHA256
e16557266a535dc246ed5de486bf28bc090b4867cf5bb13d97df68a4f1a8884b

SHA512
b1f6825265a82f7ab8f839d325deaa24cb80144578b69d8f1437aec2d010e5159de4b643cae4d58a6e644910c11b1d23390f4192c60ce83fdfb9281c371217ef

Download Submit
\ProgramData\ErrorResponder\responder.exe

Filesize
267KB

MD5
77bb261d5742e63341907e79a570eb2b

SHA1
eba5ee5b28cbe3c65b15430f81e7f105fdbb6468

SHA256
e16557266a535dc246ed5de486bf28bc090b4867cf5bb13d97df68a4f1a8884b

SHA512
b1f6825265a82f7ab8f839d325deaa24cb80144578b69d8f1437aec2d010e5159de4b643cae4d58a6e644910c11b1d23390f4192c60ce83fdfb9281c371217ef

Download Submit
\ProgramData\ErrorResponder\responder.exe

Filesize
267KB

MD5
77bb261d5742e63341907e79a570eb2b

SHA1
eba5ee5b28cbe3c65b15430f81e7f105fdbb6468

SHA256
e16557266a535dc246ed5de486bf28bc090b4867cf5bb13d97df68a4f1a8884b

SHA512
b1f6825265a82f7ab8f839d325deaa24cb80144578b69d8f1437aec2d010e5159de4b643cae4d58a6e644910c11b1d23390f4192c60ce83fdfb9281c371217ef

Download Submit
memory/900-54-0x000000000032B000-0x0000000000333000-memory.dmp

Filesize
32KB

Download
memory/900-55-0x00000000002A0000-0x00000000002AA000-memory.dmp

Filesize
40KB

Download
memory/900-56-0x00000000763E1000-0x00000000763E3000-memory.dmp

Filesize
8KB

Download
memory/900-57-0x0000000040000000-0x0000000040054000-memory.dmp

Filesize
336KB

Download
memory/900-58-0x000000000032B000-0x0000000000333000-memory.dmp

Filesize
32KB

Download
memory/900-59-0x00000000002A0000-0x00000000002AA000-memory.dmp

Filesize
40KB

Download
memory/900-64-0x000000000032B000-0x0000000000333000-memory.dmp

Filesize
32KB

Download
memory/1736-70-0x00000000000C0000-0x0000000000114000-memory.dmp

Filesize
336KB

Download
memory/1736-75-0x00000000000C0000-0x0000000000114000-memory.dmp

Filesize
336KB

Download
memory/1736-73-0x00000000000C0000-0x0000000000114000-memory.dmp

Filesize
336KB

Download
memory/1736-71-0x00000000000C0000-0x0000000000114000-memory.dmp

Filesize
336KB

Download
memory/1736-77-0x00000000000C0000-0x0000000000114000-memory.dmp

Filesize
336KB

Download
memory/1736-79-0x0000000000120000-0x0000000000121000-memory.dmp

Filesize
4KB

Download
memory/1736-83-0x00000000000C0000-0x0000000000114000-memory.dmp

Filesize
336KB

Download
memory/1936-68-0x0000000040000000-0x0000000040054000-memory.dmp

Filesize
336KB

Download
memory/1936-69-0x000000000052B000-0x0000000000533000-memory.dmp

Filesize
32KB

Download
memory/1936-67-0x000000000052B000-0x0000000000533000-memory.dmp

Filesize
32KB

Download

Analysis

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