buer | cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24

General

Target

cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24.exe
Size

1.6MB
MD5

7a4a353f71dca138e5cfb11022a8341a
SHA1

3b30f19261c8b2b8ba9873486801811dd0afa47e
SHA256

cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24
SHA512

1f2bbb338fd39474664a82e51cc34a86c815da3262e25f3177c6b631b1cc7de796ea34bbaa6ee5eea1f667b9955c5ee66fc4062b20b5806dc9e43fecb7d74d1a

Score

10^/10

buer evasion loader persistence

Malware Config

Extracted

Family

buer

C2

http://burload01.top/

http://burload02.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-1-5-21-2632097139-1792035885-811742494-1000\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/3784-131-0x000000003F710000-0x000000003FB3B000-memory.dmp	buer
behavioral2/memory/3784-133-0x000000003F710000-0x000000003FB3B000-memory.dmp	buer
behavioral2/memory/3784-136-0x000000003F710000-0x000000003FB3B000-memory.dmp	buer
behavioral2/memory/364-140-0x000000003FCD0000-0x00000000400FB000-memory.dmp	buer
behavioral2/memory/364-142-0x000000003FCD0000-0x00000000400FB000-memory.dmp	buer
behavioral2/memory/364-144-0x000000003FCD0000-0x00000000400FB000-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__	cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24.exe
Key opened	\REGISTRY\MACHINE\HARDWARE\ACPI\DSDT\VBOX__	errorResponder.exe

Executes dropped EXE 1 IoCs

pid	Process
364	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	cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24.exe
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\VideoBiosVersion	cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24.exe
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\SystemBiosVersion	errorResponder.exe
Key value queried	\REGISTRY\MACHINE\HARDWARE\DESCRIPTION\System\VideoBiosVersion	errorResponder.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-1-5-21-2632097139-1792035885-811742494-1000\Software\Wine	errorResponder.exe
Key opened	\REGISTRY\USER\S-1-5-21-2632097139-1792035885-811742494-1000\Software\Wine	cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24.exe

Suspicious use of NtSetInformationThreadHideFromDebugger 2 IoCs

pid	Process
3784	cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24.exe
364	errorResponder.exe

Program crash 2 IoCs

pid	pid_target	Process	procid_target
1896	984	WerFault.exe	87
4412	984	WerFault.exe	87

Suspicious behavior: EnumeratesProcesses 6 IoCs

pid	Process
3784	cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24.exe
3784	cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24.exe
364	errorResponder.exe
364	errorResponder.exe
364	errorResponder.exe
364	errorResponder.exe

Suspicious use of WriteProcessMemory 15 IoCs

description	pid	Process	procid_target
PID 3784 wrote to memory of 364	3784	cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24.exe	86
PID 3784 wrote to memory of 364	3784	cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24.exe	86
PID 3784 wrote to memory of 364	3784	cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24.exe	86
PID 364 wrote to memory of 984	364	errorResponder.exe	87
PID 364 wrote to memory of 984	364	errorResponder.exe	87
PID 364 wrote to memory of 984	364	errorResponder.exe	87
PID 364 wrote to memory of 984	364	errorResponder.exe	87
PID 364 wrote to memory of 984	364	errorResponder.exe	87
PID 364 wrote to memory of 984	364	errorResponder.exe	87
PID 364 wrote to memory of 984	364	errorResponder.exe	87
PID 364 wrote to memory of 984	364	errorResponder.exe	87
PID 364 wrote to memory of 984	364	errorResponder.exe	87
PID 364 wrote to memory of 984	364	errorResponder.exe	87
PID 364 wrote to memory of 984	364	errorResponder.exe	87
PID 364 wrote to memory of 984	364	errorResponder.exe	87

C:\Users\Admin\AppData\Local\Temp\cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24.exe
"C:\Users\Admin\AppData\Local\Temp\cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24.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:3784
- C:\ProgramData\ErrorResponder\errorResponder.exe
  C:\ProgramData\ErrorResponder\errorResponder.exe "C:\Users\Admin\AppData\Local\Temp\cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24.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:364
- - C:\Windows\SysWOW64\secinit.exe
    C:\ProgramData\ErrorResponder\errorResponder.exe
    3⤵
    PID:984
  - - C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 984 -s 272
      4⤵
      Program crash
      PID:1896
  - - C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 984 -s 292
      4⤵
      Program crash
      PID:4412

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 408 -p 984 -ip 984
1⤵
PID:4616

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -pss -s 432 -p 984 -ip 984
1⤵
PID:4376

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
1.6MB

MD5
7a4a353f71dca138e5cfb11022a8341a

SHA1
3b30f19261c8b2b8ba9873486801811dd0afa47e

SHA256
cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24

SHA512
1f2bbb338fd39474664a82e51cc34a86c815da3262e25f3177c6b631b1cc7de796ea34bbaa6ee5eea1f667b9955c5ee66fc4062b20b5806dc9e43fecb7d74d1a

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

Filesize
1.6MB

MD5
7a4a353f71dca138e5cfb11022a8341a

SHA1
3b30f19261c8b2b8ba9873486801811dd0afa47e

SHA256
cf8aeb8de311480bf57c259e29b39ce799304dbd3532e93b93907b1d0797ac24

SHA512
1f2bbb338fd39474664a82e51cc34a86c815da3262e25f3177c6b631b1cc7de796ea34bbaa6ee5eea1f667b9955c5ee66fc4062b20b5806dc9e43fecb7d74d1a

Download Submit
memory/364-139-0x0000000077140000-0x00000000772E3000-memory.dmp

Filesize
1.6MB

Download
memory/364-143-0x0000000077140000-0x00000000772E3000-memory.dmp

Filesize
1.6MB

Download
memory/364-144-0x000000003FCD0000-0x00000000400FB000-memory.dmp

Filesize
4.2MB

Download
memory/364-142-0x000000003FCD0000-0x00000000400FB000-memory.dmp

Filesize
4.2MB

Download
memory/364-138-0x000000003FCD0000-0x00000000400FB000-memory.dmp

Filesize
4.2MB

Download
memory/364-140-0x000000003FCD0000-0x00000000400FB000-memory.dmp

Filesize
4.2MB

Download
memory/984-146-0x0000000000B20000-0x0000000000F4B000-memory.dmp

Filesize
4.2MB

Download
memory/3784-131-0x000000003F710000-0x000000003FB3B000-memory.dmp

Filesize
4.2MB

Download
memory/3784-132-0x0000000077140000-0x00000000772E3000-memory.dmp

Filesize
1.6MB

Download
memory/3784-137-0x0000000077140000-0x00000000772E3000-memory.dmp

Filesize
1.6MB

Download
memory/3784-136-0x000000003F710000-0x000000003FB3B000-memory.dmp

Filesize
4.2MB

Download
memory/3784-133-0x000000003F710000-0x000000003FB3B000-memory.dmp

Filesize
4.2MB

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v6

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Downloads