buer | a9ec36c1b7687d5436007f2640795702ec68b69a67561f94e8507857eb1971cd

Analysis

max time kernel
13s
max time network
13s
platform
windows7_x64
resource
win7v20201028
submitted
05-03-2021 18:22

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General

Target

OfficeDocument.exe
Size

277KB
MD5

50991ebb9f7b1eb055901dc643bf50c5
SHA1

366e13a36809fef35d12e46b3f14ce950de6a7c0
SHA256

a9ec36c1b7687d5436007f2640795702ec68b69a67561f94e8507857eb1971cd
SHA512

3b5388273e490433b9bef0c445dccb628c89be7568effe0bc3f709f3f1bb021f1881846ddc96831a201b74246be87c6404acaebe9f20be6d19b74797f0a903f0

Score

10^/10

buer loader

Malware Config

Extracted

Family

buer

officesecuredocapi.com

Signatures

Buer
Buer is a new modular loader first seen in August 2019.
loader buer

Buer Loader 1 IoCs

Detects Buer loader in memory or disk.

resource	yara_rule
behavioral1/memory/1456-5-0x0000000040000000-0x0000000040009000-memory.dmp	buer

Loads dropped DLL 1 IoCs

pid	Process
1044	OfficeDocument.exe

Suspicious use of SetThreadContext 1 IoCs

description	pid	Process	procid_target
PID 1044 set thread context of 1456	1044	OfficeDocument.exe	29

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

System Information Discovery
T1082

Suspicious behavior: MapViewOfSection 1 IoCs

pid	Process
1044	OfficeDocument.exe

Suspicious use of WriteProcessMemory 5 IoCs

description	pid	Process	procid_target
PID 1044 wrote to memory of 1456	1044	OfficeDocument.exe	29
PID 1044 wrote to memory of 1456	1044	OfficeDocument.exe	29
PID 1044 wrote to memory of 1456	1044	OfficeDocument.exe	29
PID 1044 wrote to memory of 1456	1044	OfficeDocument.exe	29
PID 1044 wrote to memory of 1456	1044	OfficeDocument.exe	29

C:\Users\Admin\AppData\Local\Temp\OfficeDocument.exe
"C:\Users\Admin\AppData\Local\Temp\OfficeDocument.exe"
1⤵
- Loads dropped DLL
- Suspicious use of SetThreadContext
- Suspicious behavior: MapViewOfSection
- Suspicious use of WriteProcessMemory
PID:1044
- C:\Users\Admin\AppData\Local\Temp\OfficeDocument.exe
  "C:\Users\Admin\AppData\Local\Temp\OfficeDocument.exe"
  2⤵
  PID:1456

Network

MITRE ATT&CK Enterprise v6

Initial Access

Execution

Persistence

Privilege Escalation

Defense Evasion

Credential Access

Discovery

System Information Discovery

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Replay Monitor

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Downloads

memory/1044-2-0x00000000760A1000-0x00000000760A3000-memory.dmp

Filesize
8KB

Download
memory/1456-5-0x0000000040000000-0x0000000040009000-memory.dmp

Filesize
36KB

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