buer | 87d4ae3570608110b899d582e238ddfff0c411be980adb48b1ba7177be2b14ae

General

Target

9.exe
Size

35KB
MD5

69c7b8274b687875a08b20311147a9dd
SHA1

9ab047d53100e007c1ef89a0769a949d83d39367
SHA256

87d4ae3570608110b899d582e238ddfff0c411be980adb48b1ba7177be2b14ae
SHA512

fb13c89282524ec99e339d6d94d4fdb8f9e29d39fc72881937229737b7b90b1e3f27652f1e2c16975b08cdd70213dbc8fd092dc37e274dad0a2723dfbcbadd33

Score

10^/10

buer loader persistence

Malware Config

Extracted

Family

buer

C2

https://free-soft.cc/

https://free-pc-soft.cc/

Signatures

Buer
Buer is a new modular loader first seen in August 2019.
loader buer

Modifies WinLogon for persistence 2 TTPs 2 IoCs

persistence

Winlogon Helper DLL

T1004

Modify Registry

T1112

description	ioc	Process
Set value (str)	\REGISTRY\USER\S-1-5-21-790714498-1549421491-1643397139-1000\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\ProgramData\\ErrorResponder\\responder.exe\""	responder.exe
Set value (str)	\REGISTRY\USER\S-1-5-21-790714498-1549421491-1643397139-1000\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\ProgramData\\ErrorResponder\\responder.exe\""	secinit.exe

Buer Loader 3 IoCs

Detects Buer loader in memory or disk.

resource	yara_rule
behavioral2/files/0x001a00000001dacc-130.dat	buer
behavioral2/files/0x001a00000001dacc-131.dat	buer
behavioral2/memory/3812-133-0x00000000005E0000-0x00000000005EC000-memory.dmp	buer

Executes dropped EXE 1 IoCs

pid	Process
1616	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)	\??\I:	secinit.exe
File opened (read-only)	\??\K:	secinit.exe
File opened (read-only)	\??\O:	secinit.exe
File opened (read-only)	\??\U:	secinit.exe
File opened (read-only)	\??\Y:	secinit.exe
File opened (read-only)	\??\S:	secinit.exe
File opened (read-only)	\??\A:	secinit.exe
File opened (read-only)	\??\B:	secinit.exe
File opened (read-only)	\??\H:	secinit.exe
File opened (read-only)	\??\J:	secinit.exe
File opened (read-only)	\??\Q:	secinit.exe
File opened (read-only)	\??\W:	secinit.exe
File opened (read-only)	\??\X:	secinit.exe
File opened (read-only)	\??\Z:	secinit.exe
File opened (read-only)	\??\G:	secinit.exe
File opened (read-only)	\??\L:	secinit.exe
File opened (read-only)	\??\M:	secinit.exe
File opened (read-only)	\??\R:	secinit.exe
File opened (read-only)	\??\V:	secinit.exe
File opened (read-only)	\??\E:	secinit.exe
File opened (read-only)	\??\F:	secinit.exe
File opened (read-only)	\??\N:	secinit.exe
File opened (read-only)	\??\P:	secinit.exe
File opened (read-only)	\??\T:	secinit.exe

Suspicious behavior: EnumeratesProcesses 2 IoCs

pid	Process
3812	secinit.exe
3812	secinit.exe

Suspicious use of WriteProcessMemory 13 IoCs

description	pid	Process	procid_target
PID 3984 wrote to memory of 1616	3984	9.exe	71
PID 3984 wrote to memory of 1616	3984	9.exe	71
PID 3984 wrote to memory of 1616	3984	9.exe	71
PID 1616 wrote to memory of 3812	1616	responder.exe	72
PID 1616 wrote to memory of 3812	1616	responder.exe	72
PID 1616 wrote to memory of 3812	1616	responder.exe	72
PID 1616 wrote to memory of 3812	1616	responder.exe	72
PID 1616 wrote to memory of 3812	1616	responder.exe	72
PID 1616 wrote to memory of 3812	1616	responder.exe	72
PID 1616 wrote to memory of 3812	1616	responder.exe	72
PID 1616 wrote to memory of 3812	1616	responder.exe	72
PID 1616 wrote to memory of 3812	1616	responder.exe	72
PID 1616 wrote to memory of 3812	1616	responder.exe	72

C:\Users\Admin\AppData\Local\Temp\9.exe
"C:\Users\Admin\AppData\Local\Temp\9.exe"
1⤵
- Suspicious use of WriteProcessMemory
PID:3984
- C:\ProgramData\ErrorResponder\responder.exe
  C:\ProgramData\ErrorResponder\responder.exe "C:\Users\Admin\AppData\Local\Temp\9.exe" ensgJJ
  2⤵
  - Modifies WinLogon for persistence
  - Executes dropped EXE
  - Suspicious use of WriteProcessMemory
  PID:1616
- - C:\Windows\SysWOW64\secinit.exe
    C:\ProgramData\ErrorResponder\responder.exe
    3⤵
    - Modifies WinLogon for persistence
    - Enumerates connected drives
    - Suspicious behavior: EnumeratesProcesses
    PID:3812

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

Loading Replay Monitor...

Downloads

memory/3812-132-0x00000000005F0000-0x00000000005F1000-memory.dmp

Filesize
4KB

Download
memory/3812-133-0x00000000005E0000-0x00000000005EC000-memory.dmp

Filesize
48KB

Download

Analysis

Sharing