buer | 61feca446ab393ad4a1ccbb92623ee847b08862ef4b6cac5ff2b0c0976abc6b5

General

Target

61feca446ab393ad4a1ccbb92623ee847b08862ef4b6cac5ff2b0c0976abc6b5.exe
Size

657KB
MD5

ef93f30fe316bfdaacd4076b59b6e804
SHA1

0bfe39ff3250d91c890b50895b4612f3eac5bf4a
SHA256

61feca446ab393ad4a1ccbb92623ee847b08862ef4b6cac5ff2b0c0976abc6b5
SHA512

ad033691cc215c13ee2fb18adc82f3f90dfe0b51088588c630955436d36980d570acae0d45500e073e71cf556b37c20a40e6505983a2026fbe6a03ecb40d9b49

Score

10^/10

buer loader persistence

Malware Config

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\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\ProgramData\\a988e82d31897fcba6f8\\gennt.exe\""	gennt.exe

Buer Loader 1 IoCs

Detects Buer loader in memory or disk.

resource	yara_rule
behavioral2/memory/3532-121-0x0000000000540000-0x000000000068A000-memory.dmp	buer

Executes dropped EXE 1 IoCs

pid	Process
3532	gennt.exe

Deletes itself 1 IoCs

pid	Process
3532	gennt.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)	\??\X:	gennt.exe
File opened (read-only)	\??\J:	gennt.exe
File opened (read-only)	\??\K:	gennt.exe
File opened (read-only)	\??\M:	gennt.exe
File opened (read-only)	\??\Q:	gennt.exe
File opened (read-only)	\??\T:	gennt.exe
File opened (read-only)	\??\O:	gennt.exe
File opened (read-only)	\??\R:	gennt.exe
File opened (read-only)	\??\S:	gennt.exe
File opened (read-only)	\??\A:	gennt.exe
File opened (read-only)	\??\B:	gennt.exe
File opened (read-only)	\??\F:	gennt.exe
File opened (read-only)	\??\H:	gennt.exe
File opened (read-only)	\??\I:	gennt.exe
File opened (read-only)	\??\V:	gennt.exe
File opened (read-only)	\??\P:	gennt.exe
File opened (read-only)	\??\Z:	gennt.exe
File opened (read-only)	\??\W:	gennt.exe
File opened (read-only)	\??\Y:	gennt.exe
File opened (read-only)	\??\E:	gennt.exe
File opened (read-only)	\??\G:	gennt.exe
File opened (read-only)	\??\L:	gennt.exe
File opened (read-only)	\??\N:	gennt.exe
File opened (read-only)	\??\U:	gennt.exe

Enumerates physical storage devices 1 TTPs
Attempts to interact with connected storage/optical drive(s). Likely ransomware behaviour.

System Information Discovery
T1082

Program crash 1 IoCs

pid	pid_target	Process	procid_target
2880	1344	WerFault.exe	72

Suspicious behavior: EnumeratesProcesses 14 IoCs

pid	Process
2880	WerFault.exe
2880	WerFault.exe
2880	WerFault.exe
2880	WerFault.exe
2880	WerFault.exe
2880	WerFault.exe
2880	WerFault.exe
2880	WerFault.exe
2880	WerFault.exe
2880	WerFault.exe
2880	WerFault.exe
2880	WerFault.exe
3532	gennt.exe
3532	gennt.exe

Suspicious use of AdjustPrivilegeToken 3 IoCs

description	pid	Process
Token: SeRestorePrivilege	2880	WerFault.exe
Token: SeBackupPrivilege	2880	WerFault.exe
Token: SeDebugPrivilege	2880	WerFault.exe

Suspicious use of WriteProcessMemory 15 IoCs

description	pid	Process	procid_target
PID 2816 wrote to memory of 3532	2816	61feca446ab393ad4a1ccbb92623ee847b08862ef4b6cac5ff2b0c0976abc6b5.exe	71
PID 2816 wrote to memory of 3532	2816	61feca446ab393ad4a1ccbb92623ee847b08862ef4b6cac5ff2b0c0976abc6b5.exe	71
PID 2816 wrote to memory of 3532	2816	61feca446ab393ad4a1ccbb92623ee847b08862ef4b6cac5ff2b0c0976abc6b5.exe	71
PID 3532 wrote to memory of 1344	3532	gennt.exe	72
PID 3532 wrote to memory of 1344	3532	gennt.exe	72
PID 3532 wrote to memory of 1344	3532	gennt.exe	72
PID 3532 wrote to memory of 1344	3532	gennt.exe	72
PID 3532 wrote to memory of 1344	3532	gennt.exe	72
PID 3532 wrote to memory of 1344	3532	gennt.exe	72
PID 3532 wrote to memory of 1344	3532	gennt.exe	72
PID 3532 wrote to memory of 1344	3532	gennt.exe	72
PID 3532 wrote to memory of 1344	3532	gennt.exe	72
PID 3532 wrote to memory of 3628	3532	gennt.exe	75
PID 3532 wrote to memory of 3628	3532	gennt.exe	75
PID 3532 wrote to memory of 3628	3532	gennt.exe	75

C:\Users\Admin\AppData\Local\Temp\61feca446ab393ad4a1ccbb92623ee847b08862ef4b6cac5ff2b0c0976abc6b5.exe
"C:\Users\Admin\AppData\Local\Temp\61feca446ab393ad4a1ccbb92623ee847b08862ef4b6cac5ff2b0c0976abc6b5.exe"
1⤵
- Suspicious use of WriteProcessMemory
PID:2816
- C:\ProgramData\a988e82d31897fcba6f8\gennt.exe
  C:\ProgramData\a988e82d31897fcba6f8\gennt.exe "C:\Users\Admin\AppData\Local\Temp\61feca446ab393ad4a1ccbb92623ee847b08862ef4b6cac5ff2b0c0976abc6b5.exe" ensgJJ
  2⤵
  - Modifies WinLogon for persistence
  - Executes dropped EXE
  - Deletes itself
  - Enumerates connected drives
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of WriteProcessMemory
  PID:3532
- - C:\Windows\SysWOW64\secinit.exe
    C:\ProgramData\a988e82d31897fcba6f8\gennt.exe
    3⤵
    PID:1344
  - - C:\Windows\SysWOW64\WerFault.exe
      C:\Windows\SysWOW64\WerFault.exe -u -p 1344 -s 672
      4⤵
      Program crash
      Suspicious behavior: EnumeratesProcesses
      Suspicious use of AdjustPrivilegeToken
      PID:2880
- - C:\Windows\SysWOW64\cmd.exe
    "C:\Windows\System32\cmd.exe" powershell.exe -Command "& {Add-MpPreference -ExclusionPath C:\ProgramData\a988e82d31897fcba6f8}"
    3⤵
    PID:3628

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

2

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

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Downloads

memory/1344-124-0x0000000000A00000-0x0000000000A25000-memory.dmp

Filesize
148KB

Download
memory/1344-123-0x0000000000A30000-0x0000000000A31000-memory.dmp

Filesize
4KB

Download
memory/2816-116-0x00000000004C0000-0x000000000056E000-memory.dmp

Filesize
696KB

Download
memory/2816-115-0x00000000004C0000-0x000000000056E000-memory.dmp

Filesize
696KB

Download
memory/3532-120-0x0000000000500000-0x0000000000523000-memory.dmp

Filesize
140KB

Download
memory/3532-121-0x0000000000540000-0x000000000068A000-memory.dmp

Filesize
1.3MB

Download

Analysis

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