rustybuer | 578dc62dfa0203080da262676f28c679114d6b1c90a4ab6c07b736d9ce64e43e

General

Target

Key.exe
Size

6.8MB
MD5

963a91ca9da30098c75ecd5ab275f76c
SHA1

aff6c60c43a8900f9a9c2d11a604270c035c543c
SHA256

578dc62dfa0203080da262676f28c679114d6b1c90a4ab6c07b736d9ce64e43e
SHA512

9fc6603359f80b9e5db7a02a91ce7b22765871fff98310c0679e7f970807534cd8645dde948dc58b2ca079f8ca3b209ac675599d8f9b3edfb7c35230e674449e

Score

10^/10

rustybuer loader

Malware Config

Extracted

Family

rustybuer

C2

https://lebatyo.com/

Signatures

RustyBuer
RustyBuer is a new variant of Buer loader written in Rust.
loader rustybuer

Enumerates connected drives 3 TTPs 49 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:

secinit.exe

description	ioc	process
File opened (read-only)	\??\F:	secinit.exe
File opened (read-only)	\??\l:	secinit.exe
File opened (read-only)	\??\o:	secinit.exe
File opened (read-only)	\??\O:	secinit.exe
File opened (read-only)	\??\P:	secinit.exe
File opened (read-only)	\??\z:	secinit.exe
File opened (read-only)	\??\D:	secinit.exe
File opened (read-only)	\??\Q:	secinit.exe
File opened (read-only)	\??\R:	secinit.exe
File opened (read-only)	\??\X:	secinit.exe
File opened (read-only)	\??\B:	secinit.exe
File opened (read-only)	\??\G:	secinit.exe
File opened (read-only)	\??\r:	secinit.exe
File opened (read-only)	\??\S:	secinit.exe
File opened (read-only)	\??\x:	secinit.exe
File opened (read-only)	\??\g:	secinit.exe
File opened (read-only)	\??\U:	secinit.exe
File opened (read-only)	\??\Z:	secinit.exe
File opened (read-only)	\??\I:	secinit.exe
File opened (read-only)	\??\f:	secinit.exe
File opened (read-only)	\??\i:	secinit.exe
File opened (read-only)	\??\L:	secinit.exe
File opened (read-only)	\??\V:	secinit.exe
File opened (read-only)	\??\b:	secinit.exe
File opened (read-only)	\??\K:	secinit.exe
File opened (read-only)	\??\n:	secinit.exe
File opened (read-only)	\??\p:	secinit.exe
File opened (read-only)	\??\s:	secinit.exe
File opened (read-only)	\??\y:	secinit.exe
File opened (read-only)	\??\H:	secinit.exe
File opened (read-only)	\??\A:	secinit.exe
File opened (read-only)	\??\e:	secinit.exe
File opened (read-only)	\??\E:	secinit.exe
File opened (read-only)	\??\h:	secinit.exe
File opened (read-only)	\??\j:	secinit.exe
File opened (read-only)	\??\J:	secinit.exe
File opened (read-only)	\??\m:	secinit.exe
File opened (read-only)	\??\a:	secinit.exe
File opened (read-only)	\??\N:	secinit.exe
File opened (read-only)	\??\t:	secinit.exe
File opened (read-only)	\??\v:	secinit.exe
File opened (read-only)	\??\w:	secinit.exe
File opened (read-only)	\??\W:	secinit.exe
File opened (read-only)	\??\Y:	secinit.exe
File opened (read-only)	\??\M:	secinit.exe
File opened (read-only)	\??\q:	secinit.exe
File opened (read-only)	\??\T:	secinit.exe
File opened (read-only)	\??\u:	secinit.exe
File opened (read-only)	\??\k:	secinit.exe

Suspicious use of SetThreadContext 1 IoCs

Processes:

Key.exe

description pid process target process

PID 3200 set thread context of 3404 3200 Key.exe secinit.exe
Suspicious behavior: EnumeratesProcesses 2 IoCs

Processes:

secinit.exe

pid process

3404 secinit.exe
3404 secinit.exe

description	pid	process	target process
PID 3200 set thread context of 3404	3200	Key.exe	secinit.exe

pid	process
3404	secinit.exe
3404	secinit.exe

Suspicious use of WriteProcessMemory 9 IoCs

Processes:

Key.exe

description	pid	process	target process
PID 3200 wrote to memory of 3404	3200	Key.exe	secinit.exe
PID 3200 wrote to memory of 3404	3200	Key.exe	secinit.exe
PID 3200 wrote to memory of 3404	3200	Key.exe	secinit.exe
PID 3200 wrote to memory of 3404	3200	Key.exe	secinit.exe
PID 3200 wrote to memory of 3404	3200	Key.exe	secinit.exe
PID 3200 wrote to memory of 3404	3200	Key.exe	secinit.exe
PID 3200 wrote to memory of 3404	3200	Key.exe	secinit.exe
PID 3200 wrote to memory of 3404	3200	Key.exe	secinit.exe
PID 3200 wrote to memory of 3404	3200	Key.exe	secinit.exe

C:\Users\Admin\AppData\Local\Temp\Key.exe
"C:\Users\Admin\AppData\Local\Temp\Key.exe"
1⤵
- Suspicious use of SetThreadContext
- Suspicious use of WriteProcessMemory
PID:3200
- C:\Windows\SysWOW64\secinit.exe
  "C:\Windows\System32\secinit.exe"
  2⤵
  - Enumerates connected drives
  - Suspicious behavior: EnumeratesProcesses
  PID:3404

Network

MITRE ATT&CK Enterprise v6

Initial Access

Execution

Persistence

Privilege Escalation

Defense Evasion

Credential Access

Discovery

Peripheral Device Discovery

Query Registry

System Information Discovery

1

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Replay Monitor

Loading Replay Monitor...

Downloads

memory/3200-118-0x0000000000E90000-0x0000000000E91000-memory.dmp

Filesize
4KB

Download
memory/3404-115-0x00000000004CB45E-mapping.dmp

Download
memory/3404-114-0x0000000000400000-0x0000000000571000-memory.dmp

Filesize
1.4MB

Download
memory/3404-119-0x0000000000400000-0x0000000000571000-memory.dmp

Filesize
1.4MB

Download

Analysis

Sharing