buer | 3f5c2ca8320cbb82fc77e86eb0dc4bc208fddd20198cb5d65386f58ba7471421

General

Target

3f5c2ca8320cbb82fc77e86eb0dc4bc208fddd20198cb5d65386f58ba7471421.exe
Size

236KB
MD5

1c6713d0282f6723bc963c879fc8f7d2
SHA1

6c94575ba1d923b51cdba40ecc0553a33e766e23
SHA256

3f5c2ca8320cbb82fc77e86eb0dc4bc208fddd20198cb5d65386f58ba7471421
SHA512

24eefef37ebf1ea346a5b6a8420aa177a51667a304f1962fe3bdd0b8ee25664b6f2b7b0df15f6f29ea7b7c27f636b1f5cb9b4c31cfc0d14d43cfa48b4c6a8e61

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-1-5-21-1819626980-2277161760-1023733287-1000\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/1100-56-0x00000000001B0000-0x00000000001BA000-memory.dmp	buer
behavioral1/memory/1100-57-0x0000000040000000-0x0000000042824000-memory.dmp	buer
behavioral1/memory/1912-66-0x0000000040000000-0x0000000042824000-memory.dmp	buer

Executes dropped EXE 1 IoCs

pid	Process
1912	responder.exe

Deletes itself 1 IoCs

pid	Process
1912	responder.exe

Loads dropped DLL 2 IoCs

pid	Process
1100	3f5c2ca8320cbb82fc77e86eb0dc4bc208fddd20198cb5d65386f58ba7471421.exe
1100	3f5c2ca8320cbb82fc77e86eb0dc4bc208fddd20198cb5d65386f58ba7471421.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)	\??\I:	responder.exe
File opened (read-only)	\??\J:	responder.exe
File opened (read-only)	\??\K:	responder.exe
File opened (read-only)	\??\N:	responder.exe
File opened (read-only)	\??\O:	responder.exe
File opened (read-only)	\??\V:	responder.exe
File opened (read-only)	\??\E:	responder.exe
File opened (read-only)	\??\H:	responder.exe
File opened (read-only)	\??\L:	responder.exe
File opened (read-only)	\??\M:	responder.exe
File opened (read-only)	\??\S:	responder.exe
File opened (read-only)	\??\W:	responder.exe
File opened (read-only)	\??\Z:	responder.exe
File opened (read-only)	\??\A:	responder.exe
File opened (read-only)	\??\B:	responder.exe
File opened (read-only)	\??\X:	responder.exe
File opened (read-only)	\??\T:	responder.exe
File opened (read-only)	\??\U:	responder.exe
File opened (read-only)	\??\P:	responder.exe
File opened (read-only)	\??\Q:	responder.exe
File opened (read-only)	\??\R:	responder.exe
File opened (read-only)	\??\Y:	responder.exe
File opened (read-only)	\??\F:	responder.exe
File opened (read-only)	\??\G:	responder.exe

Program crash 1 IoCs

pid	pid_target	Process	procid_target
388	1180	WerFault.exe	28

Suspicious behavior: EnumeratesProcesses 1 IoCs

pid	Process
1912	responder.exe

Suspicious use of WriteProcessMemory 19 IoCs

description	pid	Process	procid_target
PID 1100 wrote to memory of 1912	1100	3f5c2ca8320cbb82fc77e86eb0dc4bc208fddd20198cb5d65386f58ba7471421.exe	27
PID 1100 wrote to memory of 1912	1100	3f5c2ca8320cbb82fc77e86eb0dc4bc208fddd20198cb5d65386f58ba7471421.exe	27
PID 1100 wrote to memory of 1912	1100	3f5c2ca8320cbb82fc77e86eb0dc4bc208fddd20198cb5d65386f58ba7471421.exe	27
PID 1100 wrote to memory of 1912	1100	3f5c2ca8320cbb82fc77e86eb0dc4bc208fddd20198cb5d65386f58ba7471421.exe	27
PID 1912 wrote to memory of 1180	1912	responder.exe	28
PID 1912 wrote to memory of 1180	1912	responder.exe	28
PID 1912 wrote to memory of 1180	1912	responder.exe	28
PID 1912 wrote to memory of 1180	1912	responder.exe	28
PID 1912 wrote to memory of 1180	1912	responder.exe	28
PID 1912 wrote to memory of 1180	1912	responder.exe	28
PID 1912 wrote to memory of 1180	1912	responder.exe	28
PID 1912 wrote to memory of 1180	1912	responder.exe	28
PID 1912 wrote to memory of 1180	1912	responder.exe	28
PID 1912 wrote to memory of 1180	1912	responder.exe	28
PID 1912 wrote to memory of 1180	1912	responder.exe	28
PID 1180 wrote to memory of 388	1180	secinit.exe	29
PID 1180 wrote to memory of 388	1180	secinit.exe	29
PID 1180 wrote to memory of 388	1180	secinit.exe	29
PID 1180 wrote to memory of 388	1180	secinit.exe	29

C:\Users\Admin\AppData\Local\Temp\3f5c2ca8320cbb82fc77e86eb0dc4bc208fddd20198cb5d65386f58ba7471421.exe
"C:\Users\Admin\AppData\Local\Temp\3f5c2ca8320cbb82fc77e86eb0dc4bc208fddd20198cb5d65386f58ba7471421.exe"
1⤵
- Loads dropped DLL
- Suspicious use of WriteProcessMemory
PID:1100
- C:\ProgramData\ErrorResponder\responder.exe
  C:\ProgramData\ErrorResponder\responder.exe "C:\Users\Admin\AppData\Local\Temp\3f5c2ca8320cbb82fc77e86eb0dc4bc208fddd20198cb5d65386f58ba7471421.exe" ensgJJ
  2⤵
  - Modifies WinLogon for persistence
  - Executes dropped EXE
  - Deletes itself
  - Enumerates connected drives
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of WriteProcessMemory
  PID:1912
- - C:\Windows\SysWOW64\secinit.exe
    C:\ProgramData\ErrorResponder\responder.exe
    3⤵
    - Suspicious use of WriteProcessMemory
    PID:1180
  - - C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 1180 -s 136
      4⤵
      Program crash
      PID:388

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
1c6713d0282f6723bc963c879fc8f7d2

SHA1
6c94575ba1d923b51cdba40ecc0553a33e766e23

SHA256
3f5c2ca8320cbb82fc77e86eb0dc4bc208fddd20198cb5d65386f58ba7471421

SHA512
24eefef37ebf1ea346a5b6a8420aa177a51667a304f1962fe3bdd0b8ee25664b6f2b7b0df15f6f29ea7b7c27f636b1f5cb9b4c31cfc0d14d43cfa48b4c6a8e61

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

Filesize
236KB

MD5
1c6713d0282f6723bc963c879fc8f7d2

SHA1
6c94575ba1d923b51cdba40ecc0553a33e766e23

SHA256
3f5c2ca8320cbb82fc77e86eb0dc4bc208fddd20198cb5d65386f58ba7471421

SHA512
24eefef37ebf1ea346a5b6a8420aa177a51667a304f1962fe3bdd0b8ee25664b6f2b7b0df15f6f29ea7b7c27f636b1f5cb9b4c31cfc0d14d43cfa48b4c6a8e61

Download Submit
\ProgramData\ErrorResponder\responder.exe

Filesize
236KB

MD5
1c6713d0282f6723bc963c879fc8f7d2

SHA1
6c94575ba1d923b51cdba40ecc0553a33e766e23

SHA256
3f5c2ca8320cbb82fc77e86eb0dc4bc208fddd20198cb5d65386f58ba7471421

SHA512
24eefef37ebf1ea346a5b6a8420aa177a51667a304f1962fe3bdd0b8ee25664b6f2b7b0df15f6f29ea7b7c27f636b1f5cb9b4c31cfc0d14d43cfa48b4c6a8e61

Download Submit
\ProgramData\ErrorResponder\responder.exe

Filesize
236KB

MD5
1c6713d0282f6723bc963c879fc8f7d2

SHA1
6c94575ba1d923b51cdba40ecc0553a33e766e23

SHA256
3f5c2ca8320cbb82fc77e86eb0dc4bc208fddd20198cb5d65386f58ba7471421

SHA512
24eefef37ebf1ea346a5b6a8420aa177a51667a304f1962fe3bdd0b8ee25664b6f2b7b0df15f6f29ea7b7c27f636b1f5cb9b4c31cfc0d14d43cfa48b4c6a8e61

Download Submit
memory/1100-62-0x000000000030B000-0x0000000000313000-memory.dmp

Filesize
32KB

Download
memory/1100-54-0x0000000074B51000-0x0000000074B53000-memory.dmp

Filesize
8KB

Download
memory/1100-57-0x0000000040000000-0x0000000042824000-memory.dmp

Filesize
40.1MB

Download
memory/1100-55-0x000000000030B000-0x0000000000313000-memory.dmp

Filesize
32KB

Download
memory/1100-56-0x00000000001B0000-0x00000000001BA000-memory.dmp

Filesize
40KB

Download
memory/1180-80-0x0000000000750000-0x0000000002F74000-memory.dmp

Filesize
40.1MB

Download
memory/1180-67-0x0000000000750000-0x0000000002F74000-memory.dmp

Filesize
40.1MB

Download
memory/1180-68-0x0000000000750000-0x0000000002F74000-memory.dmp

Filesize
40.1MB

Download
memory/1180-70-0x0000000000750000-0x0000000002F74000-memory.dmp

Filesize
40.1MB

Download
memory/1180-72-0x0000000000750000-0x0000000002F74000-memory.dmp

Filesize
40.1MB

Download
memory/1180-74-0x0000000000750000-0x0000000002F74000-memory.dmp

Filesize
40.1MB

Download
memory/1180-76-0x0000000000080000-0x0000000000081000-memory.dmp

Filesize
4KB

Download
memory/1912-66-0x0000000040000000-0x0000000042824000-memory.dmp

Filesize
40.1MB

Download
memory/1912-65-0x00000000002EB000-0x00000000002F3000-memory.dmp

Filesize
32KB

Download

Analysis

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