buer | e212e5bc428a0bca4615205f07c10d4e57dc881a2f32a9b8aeec040169435aa1

General

Target

DocumentPreview.exe
Size

146KB
MD5

db3c2530d727bac602e6c41cb3e60562
SHA1

0d62d5a5fba84c1e826591f27892466a1cd59257
SHA256

e212e5bc428a0bca4615205f07c10d4e57dc881a2f32a9b8aeec040169435aa1
SHA512

03e25d32a262c88ec2cf9303b7835da93b321a1d2a092531c96df8d95065944250f63c075792ca72b6d2a12d60c492782ba516712fbca0bf3b0239477b6b06e8

Score

10^/10

buer loader persistence

Malware Config

Extracted

Family

buer

C2

https://162.244.81.87/

http://162.244.81.87:8080/

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

Processes:

gennt.exe

description	ioc	process
Set value (str)	\REGISTRY\MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\ProgramData\\489b1a91ca40d281ca53\\gennt.exe\""	gennt.exe

Buer Loader 1 IoCs

Detects Buer loader in memory or disk.

Processes:

resource	yara_rule
behavioral2/memory/3908-0-0x00000000001E0000-0x00000000001EC000-memory.dmp	buer

Executes dropped EXE 1 IoCs

Processes:

gennt.exe

pid process

2200 gennt.exe
Deletes itself 1 IoCs

Processes:

gennt.exe

pid process

2200 gennt.exe

pid	process
2200	gennt.exe

pid	process
2200	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

Processes:

gennt.exe

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

Processes:

WerFault.exe

pid pid_target process target process

3916 2864 WerFault.exe secinit.exe

pid	pid_target	process	target process
3916	2864	WerFault.exe	secinit.exe

Suspicious behavior: EnumeratesProcesses 15 IoCs

Processes:

WerFault.exegennt.exe

pid	process
3916	WerFault.exe
3916	WerFault.exe
3916	WerFault.exe
3916	WerFault.exe
3916	WerFault.exe
3916	WerFault.exe
3916	WerFault.exe
3916	WerFault.exe
3916	WerFault.exe
3916	WerFault.exe
3916	WerFault.exe
3916	WerFault.exe
3916	WerFault.exe
2200	gennt.exe
2200	gennt.exe

Suspicious use of AdjustPrivilegeToken 3 IoCs

Processes:

WerFault.exe

description pid process

Token: SeRestorePrivilege 3916 WerFault.exe
Token: SeBackupPrivilege 3916 WerFault.exe
Token: SeDebugPrivilege 3916 WerFault.exe

description	pid	process
Token: SeRestorePrivilege	3916	WerFault.exe
Token: SeBackupPrivilege	3916	WerFault.exe
Token: SeDebugPrivilege	3916	WerFault.exe

Suspicious use of WriteProcessMemory 16 IoCs

Processes:

DocumentPreview.exegennt.exe

description	pid	process	target process
PID 3908 wrote to memory of 2200	3908	DocumentPreview.exe	gennt.exe
PID 3908 wrote to memory of 2200	3908	DocumentPreview.exe	gennt.exe
PID 3908 wrote to memory of 2200	3908	DocumentPreview.exe	gennt.exe
PID 2200 wrote to memory of 2864	2200	gennt.exe	secinit.exe
PID 2200 wrote to memory of 2864	2200	gennt.exe	secinit.exe
PID 2200 wrote to memory of 2864	2200	gennt.exe	secinit.exe
PID 2200 wrote to memory of 2864	2200	gennt.exe	secinit.exe
PID 2200 wrote to memory of 2864	2200	gennt.exe	secinit.exe
PID 2200 wrote to memory of 2864	2200	gennt.exe	secinit.exe
PID 2200 wrote to memory of 2864	2200	gennt.exe	secinit.exe
PID 2200 wrote to memory of 2864	2200	gennt.exe	secinit.exe
PID 2200 wrote to memory of 2864	2200	gennt.exe	secinit.exe
PID 2200 wrote to memory of 2864	2200	gennt.exe	secinit.exe
PID 2200 wrote to memory of 3992	2200	gennt.exe	cmd.exe
PID 2200 wrote to memory of 3992	2200	gennt.exe	cmd.exe
PID 2200 wrote to memory of 3992	2200	gennt.exe	cmd.exe

C:\Users\Admin\AppData\Local\Temp\DocumentPreview.exe
"C:\Users\Admin\AppData\Local\Temp\DocumentPreview.exe"
1⤵
- Suspicious use of WriteProcessMemory
PID:3908

C:\ProgramData\489b1a91ca40d281ca53\gennt.exe
C:\ProgramData\489b1a91ca40d281ca53\gennt.exe "C:\Users\Admin\AppData\Local\Temp\DocumentPreview.exe" ensgJJ
2⤵
- Modifies WinLogon for persistence
- Executes dropped EXE
- Deletes itself
- Enumerates connected drives
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of WriteProcessMemory
PID:2200

C:\Windows\SysWOW64\secinit.exe
C:\ProgramData\489b1a91ca40d281ca53\gennt.exe
3⤵
PID:2864

C:\Windows\SysWOW64\WerFault.exe
C:\Windows\SysWOW64\WerFault.exe -u -p 2864 -s 356
4⤵
- Program crash
- Suspicious behavior: EnumeratesProcesses
- Suspicious use of AdjustPrivilegeToken
PID:3916

C:\Windows\SysWOW64\cmd.exe
"C:\Windows\System32\cmd.exe" powershell.exe -Command "& {Add-MpPreference -ExclusionPath C:\ProgramData\489b1a91ca40d281ca53}"
3⤵
PID:3992

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

C:\ProgramData\489b1a91ca40d281ca53\gennt.exe

MD5
db3c2530d727bac602e6c41cb3e60562

SHA1
0d62d5a5fba84c1e826591f27892466a1cd59257

SHA256
e212e5bc428a0bca4615205f07c10d4e57dc881a2f32a9b8aeec040169435aa1

SHA512
03e25d32a262c88ec2cf9303b7835da93b321a1d2a092531c96df8d95065944250f63c075792ca72b6d2a12d60c492782ba516712fbca0bf3b0239477b6b06e8

Download Submit
C:\ProgramData\489b1a91ca40d281ca53\gennt.exe

MD5
db3c2530d727bac602e6c41cb3e60562

SHA1
0d62d5a5fba84c1e826591f27892466a1cd59257

SHA256
e212e5bc428a0bca4615205f07c10d4e57dc881a2f32a9b8aeec040169435aa1

SHA512
03e25d32a262c88ec2cf9303b7835da93b321a1d2a092531c96df8d95065944250f63c075792ca72b6d2a12d60c492782ba516712fbca0bf3b0239477b6b06e8

Download Submit
memory/2200-1-0x0000000000000000-mapping.dmp

Download
memory/2864-10-0x0000000000000000-mapping.dmp

Download
memory/2864-5-0x0000000000000000-mapping.dmp

Download
memory/2864-8-0x0000000000000000-mapping.dmp

Download
memory/2864-9-0x0000000000000000-mapping.dmp

Download
memory/2864-11-0x0000000000000000-mapping.dmp

Download
memory/2864-12-0x0000000000000000-mapping.dmp

Download
memory/3908-0-0x00000000001E0000-0x00000000001EC000-memory.dmp

Filesize
48KB

Download
memory/3916-6-0x00000000043D0000-0x00000000043D1000-memory.dmp

Filesize
4KB

Download
memory/3916-7-0x00000000043D0000-0x00000000043D1000-memory.dmp

Filesize
4KB

Download
memory/3916-14-0x0000000004A20000-0x0000000004A21000-memory.dmp

Filesize
4KB

Download
memory/3992-13-0x0000000000000000-mapping.dmp

Download

Analysis

Sharing

General

Malware Config

Extracted

Signatures

Processes

Network

MITRE ATT&CK Enterprise v6

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Downloads