buer | 4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27

General

Target

4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27.exe
Size

1.8MB
MD5

29e83eb08c474cf1a86c910cb09ddf68
SHA1

3ff2d663dfd76dbeed99deb4136f1ec5f924e94f
SHA256

4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27
SHA512

bda8b5501954758dd3357124041aa1e66eda227181c47830b617d41097b1f4ba87733b1a4314726ebc952c94b25c9b07cacb10eb271e70c07b09265dd3a45bd3

Score

10^/10

buer evasion loader persistence

Malware Config

Extracted

Family

buer

C2

http://bbload01.top/

http://bbload02.top/

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-1-5-21-1809750270-3141839489-3074374771-1000\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\ProgramData\\ErrorResponder\\errorResponder.exe\""	errorResponder.exe

Buer Loader 6 IoCs

Detects Buer loader in memory or disk.

loader

resource	yara_rule
behavioral2/memory/3212-130-0x000000003F780000-0x000000003FC08000-memory.dmp	buer
behavioral2/memory/3212-132-0x000000003F780000-0x000000003FC08000-memory.dmp	buer
behavioral2/memory/3212-135-0x000000003F780000-0x000000003FC08000-memory.dmp	buer
behavioral2/memory/3816-140-0x000000003FFD0000-0x0000000040458000-memory.dmp	buer
behavioral2/memory/3816-141-0x000000003FFD0000-0x0000000040458000-memory.dmp	buer
behavioral2/memory/3816-142-0x000000003FFD0000-0x0000000040458000-memory.dmp	buer

Identifies VirtualBox via ACPI registry values (likely anti-VM) 2 TTPs 2 IoCs

evasion

Query Registry

T1012

Virtualization/Sandbox Evasion

T1497

description	ioc	Process
Key opened	\REGISTRY\MACHINE\HARDWARE\ACPI\DSDT\VBOX__	4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27.exe
Key opened	\REGISTRY\MACHINE\HARDWARE\ACPI\DSDT\VBOX__	errorResponder.exe

Executes dropped EXE 1 IoCs

pid	Process
3816	errorResponder.exe

Checks BIOS information in registry 2 TTPs 4 IoCs

BIOS information is often read in order to detect sandboxing environments.

Query Registry

T1012

System Information Discovery

T1082

description	ioc	Process
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\SystemBiosVersion	errorResponder.exe
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\VideoBiosVersion	errorResponder.exe
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\SystemBiosVersion	4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27.exe
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\VideoBiosVersion	4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27.exe

Identifies Wine through registry keys 2 TTPs 2 IoCs

Wine is a compatibility layer capable of running Windows applications, which can be used as sandboxing environment.

evasion

Query Registry

T1012

Virtualization/Sandbox Evasion

T1497

description	ioc	Process
Key opened	\REGISTRY\USER\S-1-5-21-1809750270-3141839489-3074374771-1000\Software\Wine	errorResponder.exe
Key opened	\REGISTRY\USER\S-1-5-21-1809750270-3141839489-3074374771-1000\Software\Wine	4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27.exe

Suspicious use of NtSetInformationThreadHideFromDebugger 2 IoCs

pid	Process
3212	4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27.exe
3816	errorResponder.exe

Program crash 2 IoCs

pid	pid_target	Process	procid_target
3388	1316	WerFault.exe	91
3116	1316	WerFault.exe	91

Suspicious behavior: EnumeratesProcesses 6 IoCs

pid	Process
3212	4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27.exe
3212	4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27.exe
3816	errorResponder.exe
3816	errorResponder.exe
3816	errorResponder.exe
3816	errorResponder.exe

Suspicious use of WriteProcessMemory 15 IoCs

description	pid	Process	procid_target
PID 3212 wrote to memory of 3816	3212	4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27.exe	90
PID 3212 wrote to memory of 3816	3212	4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27.exe	90
PID 3212 wrote to memory of 3816	3212	4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27.exe	90
PID 3816 wrote to memory of 1316	3816	errorResponder.exe	91
PID 3816 wrote to memory of 1316	3816	errorResponder.exe	91
PID 3816 wrote to memory of 1316	3816	errorResponder.exe	91
PID 3816 wrote to memory of 1316	3816	errorResponder.exe	91
PID 3816 wrote to memory of 1316	3816	errorResponder.exe	91
PID 3816 wrote to memory of 1316	3816	errorResponder.exe	91
PID 3816 wrote to memory of 1316	3816	errorResponder.exe	91
PID 3816 wrote to memory of 1316	3816	errorResponder.exe	91
PID 3816 wrote to memory of 1316	3816	errorResponder.exe	91
PID 3816 wrote to memory of 1316	3816	errorResponder.exe	91
PID 3816 wrote to memory of 1316	3816	errorResponder.exe	91
PID 3816 wrote to memory of 1316	3816	errorResponder.exe	91

C:\Users\Admin\AppData\Local\Temp\4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27.exe
"C:\Users\Admin\AppData\Local\Temp\4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27.exe"
1⤵
- Identifies VirtualBox via ACPI registry values (likely anti-VM)
- Checks BIOS information in registry
- Identifies Wine through registry keys
- Suspicious use of NtSetInformationThreadHideFromDebugger
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of WriteProcessMemory
PID:3212
- C:\ProgramData\ErrorResponder\errorResponder.exe
  C:\ProgramData\ErrorResponder\errorResponder.exe "C:\Users\Admin\AppData\Local\Temp\4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27.exe" ensgJJ
  2⤵
  - Modifies WinLogon for persistence
  - Identifies VirtualBox via ACPI registry values (likely anti-VM)
  - Executes dropped EXE
  - Checks BIOS information in registry
  - Identifies Wine through registry keys
  - Suspicious use of NtSetInformationThreadHideFromDebugger
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of WriteProcessMemory
  PID:3816
- - C:\Windows\SysWOW64\secinit.exe
    C:\ProgramData\ErrorResponder\errorResponder.exe
    3⤵
    PID:1316
  - - C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 1316 -s 272
      4⤵
      Program crash
      PID:3388
  - - C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 1316 -s 280
      4⤵
      Program crash
      PID:3116

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 408 -p 1316 -ip 1316
1⤵
PID:4728

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 452 -p 1316 -ip 1316
1⤵
PID:1972

Network

MITRE ATT&CK Enterprise v6

Initial Access

Execution

Persistence

Winlogon Helper DLL

1

T1004

Privilege Escalation

Defense Evasion

Modify Registry

1

T1112

Virtualization/Sandbox Evasion

2

T1497

Credential Access

Discovery

Query Registry

3

T1012

System Information Discovery

1

T1082

Virtualization/Sandbox Evasion

2

T1497

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

C:\ProgramData\ErrorResponder\errorResponder.exe

Filesize
1.8MB

MD5
29e83eb08c474cf1a86c910cb09ddf68

SHA1
3ff2d663dfd76dbeed99deb4136f1ec5f924e94f

SHA256
4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27

SHA512
bda8b5501954758dd3357124041aa1e66eda227181c47830b617d41097b1f4ba87733b1a4314726ebc952c94b25c9b07cacb10eb271e70c07b09265dd3a45bd3

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

Filesize
1.8MB

MD5
29e83eb08c474cf1a86c910cb09ddf68

SHA1
3ff2d663dfd76dbeed99deb4136f1ec5f924e94f

SHA256
4f9daccbc02a2fa0bcc5149af49dcef672fdf2683e9f5ab471a0aa633c386a27

SHA512
bda8b5501954758dd3357124041aa1e66eda227181c47830b617d41097b1f4ba87733b1a4314726ebc952c94b25c9b07cacb10eb271e70c07b09265dd3a45bd3

Download Submit
memory/1316-144-0x0000000000E30000-0x00000000012B8000-memory.dmp

Filesize
4.5MB

Download
memory/3212-131-0x0000000077020000-0x00000000771C3000-memory.dmp

Filesize
1.6MB

Download
memory/3212-132-0x000000003F780000-0x000000003FC08000-memory.dmp

Filesize
4.5MB

Download
memory/3212-130-0x000000003F780000-0x000000003FC08000-memory.dmp

Filesize
4.5MB

Download
memory/3212-135-0x000000003F780000-0x000000003FC08000-memory.dmp

Filesize
4.5MB

Download
memory/3212-136-0x0000000077020000-0x00000000771C3000-memory.dmp

Filesize
1.6MB

Download
memory/3816-140-0x000000003FFD0000-0x0000000040458000-memory.dmp

Filesize
4.5MB

Download
memory/3816-141-0x000000003FFD0000-0x0000000040458000-memory.dmp

Filesize
4.5MB

Download
memory/3816-142-0x000000003FFD0000-0x0000000040458000-memory.dmp

Filesize
4.5MB

Download
memory/3816-139-0x0000000077020000-0x00000000771C3000-memory.dmp

Filesize
1.6MB

Download
memory/3816-137-0x000000003FFD0000-0x0000000040458000-memory.dmp

Filesize
4.5MB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v6

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Downloads