buer | 87d4ae3570608110b899d582e238ddfff0c411be980adb48b1ba7177be2b14ae | Triage

Analysis

max time kernel
4294195s
max time network
137s
platform
windows7_x64
resource
win7-20220223-en
submitted
24/02/2022, 23:02

Sharing

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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 1 IoCs

Winlogon Helper DLL

Modify Registry

description	ioc	Process
Set value (str)	\REGISTRY\USER\S-1-5-21-1405931862-909307831-4085185274-1000\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.

resource	yara_rule
behavioral1/files/0x0004000000004ed7-55.dat	buer
behavioral1/files/0x0004000000004ed7-57.dat	buer
behavioral1/files/0x0004000000004ed7-56.dat	buer
behavioral1/files/0x0004000000004ed7-59.dat	buer

Executes dropped EXE 1 IoCs

pid	Process
580	responder.exe

Deletes itself 1 IoCs

pid	Process
580	responder.exe

Loads dropped DLL 2 IoCs

pid	Process
1104	9.exe
1104	9.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

Peripheral Device Discovery

System Information Discovery

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

Suspicious behavior: EnumeratesProcesses 1 IoCs

pid	Process
580	responder.exe

Suspicious use of WriteProcessMemory 8 IoCs

description	pid	Process	procid_target
PID 1104 wrote to memory of 580	1104	9.exe	29
PID 1104 wrote to memory of 580	1104	9.exe	29
PID 1104 wrote to memory of 580	1104	9.exe	29
PID 1104 wrote to memory of 580	1104	9.exe	29
PID 580 wrote to memory of 1368	580	responder.exe	30
PID 580 wrote to memory of 1368	580	responder.exe	30
PID 580 wrote to memory of 1368	580	responder.exe	30
PID 580 wrote to memory of 1368	580	responder.exe	30

C:\Users\Admin\AppData\Local\Temp\9.exe
"C:\Users\Admin\AppData\Local\Temp\9.exe"
1⤵
- Loads dropped DLL
- Suspicious use of WriteProcessMemory
PID:1104
- 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
  - Deletes itself
  - Enumerates connected drives
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of WriteProcessMemory
  PID:580
- - C:\Windows\SysWOW64\secinit.exe
    C:\ProgramData\ErrorResponder\responder.exe
    3⤵
    PID:1368

Network

MITRE ATT&CK Enterprise v6

Initial Access

Execution

Persistence

Winlogon Helper DLL

Privilege Escalation

Defense Evasion

Modify Registry

Credential Access

Discovery

Peripheral Device Discovery

Query Registry

System Information Discovery

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

memory/1104-54-0x0000000076771000-0x0000000076773000-memory.dmp

Filesize
8KB

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