buer | 7c70ee2493d0ccc41cf42d9ef1f478d235bb09fa98eb1e991d7f4bccac818bf0 | Triage

Analysis

max time kernel
4294182s
max time network
124s
platform
windows7_x64
resource
win7-20220223-en
submitted
24-02-2022 22:57

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General

Target

2.exe
Size

36KB
MD5

4d85e1d2cff1f97e149e345a19928ad9
SHA1

2c1c6df0d80940bed3576ba89bd8b0f29654bb17
SHA256

7c70ee2493d0ccc41cf42d9ef1f478d235bb09fa98eb1e991d7f4bccac818bf0
SHA512

d0afa20c1cf1fbdb197dc846e862478fa156b1331b4b4cf1e96520c7981c87de2c25c0dbdebcf6749212c56f70443b3792a133e1261210cf1298358535221f1f

Score

10^/10

buer loader persistence

Malware Config

Extracted

Family

buer

C2

https://gstatiknetiplist.cc/

https://gstatiknetiplist.com/

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

Executes dropped EXE 1 IoCs

pid	Process
1748	responder.exe

Deletes itself 1 IoCs

pid	Process
1748	responder.exe

Loads dropped DLL 2 IoCs

pid	Process
1236	2.exe
1236	2.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)	\??\I:	responder.exe
File opened (read-only)	\??\J:	responder.exe
File opened (read-only)	\??\M:	responder.exe
File opened (read-only)	\??\N:	responder.exe
File opened (read-only)	\??\R:	responder.exe
File opened (read-only)	\??\A:	responder.exe
File opened (read-only)	\??\B:	responder.exe
File opened (read-only)	\??\H:	responder.exe
File opened (read-only)	\??\T:	responder.exe
File opened (read-only)	\??\U:	responder.exe
File opened (read-only)	\??\S:	responder.exe
File opened (read-only)	\??\W:	responder.exe
File opened (read-only)	\??\Z:	responder.exe
File opened (read-only)	\??\E:	responder.exe
File opened (read-only)	\??\F:	responder.exe
File opened (read-only)	\??\P:	responder.exe
File opened (read-only)	\??\L:	responder.exe
File opened (read-only)	\??\X:	responder.exe
File opened (read-only)	\??\Y:	responder.exe
File opened (read-only)	\??\Q:	responder.exe
File opened (read-only)	\??\V:	responder.exe
File opened (read-only)	\??\G:	responder.exe
File opened (read-only)	\??\K:	responder.exe
File opened (read-only)	\??\O:	responder.exe

Suspicious behavior: EnumeratesProcesses 1 IoCs

pid	Process
1748	responder.exe

Suspicious use of WriteProcessMemory 8 IoCs

description	pid	Process	procid_target
PID 1236 wrote to memory of 1748	1236	2.exe	29
PID 1236 wrote to memory of 1748	1236	2.exe	29
PID 1236 wrote to memory of 1748	1236	2.exe	29
PID 1236 wrote to memory of 1748	1236	2.exe	29
PID 1748 wrote to memory of 1076	1748	responder.exe	30
PID 1748 wrote to memory of 1076	1748	responder.exe	30
PID 1748 wrote to memory of 1076	1748	responder.exe	30
PID 1748 wrote to memory of 1076	1748	responder.exe	30

C:\Users\Admin\AppData\Local\Temp\2.exe
"C:\Users\Admin\AppData\Local\Temp\2.exe"
1⤵
- Loads dropped DLL
- Suspicious use of WriteProcessMemory
PID:1236
- C:\ProgramData\ErrorResponder\responder.exe
  C:\ProgramData\ErrorResponder\responder.exe "C:\Users\Admin\AppData\Local\Temp\2.exe" ensgJJ
  2⤵
  - Modifies WinLogon for persistence
  - Executes dropped EXE
  - Deletes itself
  - Enumerates connected drives
  - Suspicious behavior: EnumeratesProcesses
  - Suspicious use of WriteProcessMemory
  PID:1748
- - C:\Windows\SysWOW64\secinit.exe
    C:\ProgramData\ErrorResponder\responder.exe
    3⤵
    PID:1076

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/1236-54-0x0000000075F71000-0x0000000075F73000-memory.dmp

Filesize
8KB

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