buer | 3524a53569a7016bbb9f2b4793d0da464e88410fffd65b9f137be015e0a06874

General

Target

3524a53569a7016bbb9f2b4793d0da464e88410fffd65b9f137be015e0a06874.exe
Size

183KB
MD5

7b5b7a530af5c23b4828f9f0eb81f3a3
SHA1

04e848ea25b3a4fe7329d6f545216f6abc4a8f51
SHA256

3524a53569a7016bbb9f2b4793d0da464e88410fffd65b9f137be015e0a06874
SHA512

fc1c11a556dcc8ee37fb71a9ab6b4ab6565f58c9c9a9d791ab2658c03bc3ceba0c1d2ca328880ceabbfa43caa2db693cbee43653bc2d87050f119399cf0cdbb6

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

Buer Loader 5 IoCs

Detects Buer loader in memory or disk.

loader

resource	yara_rule
behavioral2/memory/1140-131-0x0000000000030000-0x000000000003A000-memory.dmp	buer
behavioral2/memory/1140-132-0x0000000040000000-0x00000000429E4000-memory.dmp	buer
behavioral2/memory/1140-134-0x0000000000030000-0x000000000003A000-memory.dmp	buer
behavioral2/memory/1140-135-0x0000000040000000-0x00000000429E4000-memory.dmp	buer
behavioral2/memory/4444-140-0x0000000040000000-0x00000000429E4000-memory.dmp	buer

Executes dropped EXE 1 IoCs

pid	Process
4444	responder.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)	\??\B:	responder.exe
File opened (read-only)	\??\J:	responder.exe
File opened (read-only)	\??\K:	responder.exe
File opened (read-only)	\??\Q:	responder.exe
File opened (read-only)	\??\S:	responder.exe
File opened (read-only)	\??\Y:	responder.exe
File opened (read-only)	\??\H:	responder.exe
File opened (read-only)	\??\I:	responder.exe
File opened (read-only)	\??\L:	responder.exe
File opened (read-only)	\??\R:	responder.exe
File opened (read-only)	\??\U:	responder.exe
File opened (read-only)	\??\W:	responder.exe
File opened (read-only)	\??\A:	responder.exe
File opened (read-only)	\??\M:	responder.exe
File opened (read-only)	\??\O:	responder.exe
File opened (read-only)	\??\V:	responder.exe
File opened (read-only)	\??\Z:	responder.exe
File opened (read-only)	\??\X:	responder.exe
File opened (read-only)	\??\E:	responder.exe
File opened (read-only)	\??\F:	responder.exe
File opened (read-only)	\??\G:	responder.exe
File opened (read-only)	\??\N:	responder.exe
File opened (read-only)	\??\P:	responder.exe
File opened (read-only)	\??\T:	responder.exe

Program crash 2 IoCs

pid	pid_target	Process	procid_target
4476	1140	WerFault.exe	80
216	4108	WerFault.exe	93

Suspicious behavior: EnumeratesProcesses 2 IoCs

pid	Process
4444	responder.exe
4444	responder.exe

Suspicious use of WriteProcessMemory 13 IoCs

description	pid	Process	procid_target
PID 1140 wrote to memory of 4444	1140	3524a53569a7016bbb9f2b4793d0da464e88410fffd65b9f137be015e0a06874.exe	89
PID 1140 wrote to memory of 4444	1140	3524a53569a7016bbb9f2b4793d0da464e88410fffd65b9f137be015e0a06874.exe	89
PID 1140 wrote to memory of 4444	1140	3524a53569a7016bbb9f2b4793d0da464e88410fffd65b9f137be015e0a06874.exe	89
PID 4444 wrote to memory of 4108	4444	responder.exe	93
PID 4444 wrote to memory of 4108	4444	responder.exe	93
PID 4444 wrote to memory of 4108	4444	responder.exe	93
PID 4444 wrote to memory of 4108	4444	responder.exe	93
PID 4444 wrote to memory of 4108	4444	responder.exe	93
PID 4444 wrote to memory of 4108	4444	responder.exe	93
PID 4444 wrote to memory of 4108	4444	responder.exe	93
PID 4444 wrote to memory of 4108	4444	responder.exe	93
PID 4444 wrote to memory of 4108	4444	responder.exe	93
PID 4444 wrote to memory of 4108	4444	responder.exe	93

C:\Users\Admin\AppData\Local\Temp\3524a53569a7016bbb9f2b4793d0da464e88410fffd65b9f137be015e0a06874.exe
"C:\Users\Admin\AppData\Local\Temp\3524a53569a7016bbb9f2b4793d0da464e88410fffd65b9f137be015e0a06874.exe"
1⤵
- Suspicious use of WriteProcessMemory
PID:1140
- C:\ProgramData\ErrorResponder\responder.exe
  C:\ProgramData\ErrorResponder\responder.exe "C:\Users\Admin\AppData\Local\Temp\3524a53569a7016bbb9f2b4793d0da464e88410fffd65b9f137be015e0a06874.exe" ensgJJ
  2⤵
  - Modifies WinLogon for persistence
  - Executes dropped EXE
  - Enumerates connected drives
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of WriteProcessMemory
  PID:4444
- - C:\Windows\SysWOW64\secinit.exe
    C:\ProgramData\ErrorResponder\responder.exe
    3⤵
    PID:4108
  - - C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 4108 -s 220
      4⤵
      Program crash
      PID:216
- C:\Windows\SysWOW64\WerFault.exe
  C:\Windows\SysWOW64\WerFault.exe -u -p 1140 -s 440
  2⤵
  - Program crash
  PID:4476

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 444 -p 1140 -ip 1140
1⤵
PID:5016

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 520 -p 4108 -ip 4108
1⤵
PID:4412

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
183KB

MD5
7b5b7a530af5c23b4828f9f0eb81f3a3

SHA1
04e848ea25b3a4fe7329d6f545216f6abc4a8f51

SHA256
3524a53569a7016bbb9f2b4793d0da464e88410fffd65b9f137be015e0a06874

SHA512
fc1c11a556dcc8ee37fb71a9ab6b4ab6565f58c9c9a9d791ab2658c03bc3ceba0c1d2ca328880ceabbfa43caa2db693cbee43653bc2d87050f119399cf0cdbb6

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

Filesize
183KB

MD5
7b5b7a530af5c23b4828f9f0eb81f3a3

SHA1
04e848ea25b3a4fe7329d6f545216f6abc4a8f51

SHA256
3524a53569a7016bbb9f2b4793d0da464e88410fffd65b9f137be015e0a06874

SHA512
fc1c11a556dcc8ee37fb71a9ab6b4ab6565f58c9c9a9d791ab2658c03bc3ceba0c1d2ca328880ceabbfa43caa2db693cbee43653bc2d87050f119399cf0cdbb6

Download Submit
memory/1140-142-0x00000000006A2000-0x00000000006AA000-memory.dmp

Filesize
32KB

Download
memory/1140-131-0x0000000000030000-0x000000000003A000-memory.dmp

Filesize
40KB

Download
memory/1140-132-0x0000000040000000-0x00000000429E4000-memory.dmp

Filesize
41.9MB

Download
memory/1140-133-0x00000000006A2000-0x00000000006AA000-memory.dmp

Filesize
32KB

Download
memory/1140-134-0x0000000000030000-0x000000000003A000-memory.dmp

Filesize
40KB

Download
memory/1140-135-0x0000000040000000-0x00000000429E4000-memory.dmp

Filesize
41.9MB

Download
memory/1140-130-0x00000000006A2000-0x00000000006AA000-memory.dmp

Filesize
32KB

Download
memory/4108-144-0x0000000000880000-0x0000000003264000-memory.dmp

Filesize
41.9MB

Download
memory/4444-141-0x0000000000633000-0x000000000063B000-memory.dmp

Filesize
32KB

Download
memory/4444-140-0x0000000040000000-0x00000000429E4000-memory.dmp

Filesize
41.9MB

Download
memory/4444-139-0x0000000000633000-0x000000000063B000-memory.dmp

Filesize
32KB

Download

Analysis

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