buer | f2a883a0e4b01c72b0f063df3be5a0102e5c8fbaedc39c8d35c632b200599283

Analysis

max time kernel
150s
max time network
152s
platform
windows7_x64
resource
win7v20201028
submitted
02-03-2021 20:23

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General

Target

ServApi.exe
Size

281KB
MD5

19ca9bf5eebc9e2f0bd3230f262348fd
SHA1

e8157d7e277ccf04de3476c1845cd597c112786e
SHA256

f2a883a0e4b01c72b0f063df3be5a0102e5c8fbaedc39c8d35c632b200599283
SHA512

636859bd44528e75e5c6c25ad4fce12e0482fdd0de3798c863efbf4326e77db184b1354fc5433672239dee4350a0fc12427acc9a4bedfd17487e96ee5e397d72

Score

10^/10

buer loader

Malware Config

Extracted

Family

buer

verstudiosan.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.

Processes:

resource	yara_rule
behavioral1/memory/1712-5-0x0000000040000000-0x0000000040009000-memory.dmp	buer

Loads dropped DLL 1 IoCs

Processes:

ServApi.exe

pid process

1340 ServApi.exe
Suspicious use of SetThreadContext 1 IoCs

Processes:

ServApi.exe

description pid process target process

PID 1340 set thread context of 1712 1340 ServApi.exe ServApi.exe
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

Processes:

ServApi.exe

pid process

1340 ServApi.exe

pid	process
1340	ServApi.exe

description	pid	process	target process
PID 1340 set thread context of 1712	1340	ServApi.exe	ServApi.exe

pid	process
1340	ServApi.exe

Suspicious use of WriteProcessMemory 8 IoCs

Processes:

ServApi.exe

description	pid	process	target process
PID 1340 wrote to memory of 1712	1340	ServApi.exe	ServApi.exe
PID 1340 wrote to memory of 1712	1340	ServApi.exe	ServApi.exe
PID 1340 wrote to memory of 1712	1340	ServApi.exe	ServApi.exe
PID 1340 wrote to memory of 1712	1340	ServApi.exe	ServApi.exe
PID 1340 wrote to memory of 1712	1340	ServApi.exe	ServApi.exe
PID 1340 wrote to memory of 1712	1340	ServApi.exe	ServApi.exe
PID 1340 wrote to memory of 1712	1340	ServApi.exe	ServApi.exe
PID 1340 wrote to memory of 1712	1340	ServApi.exe	ServApi.exe

C:\Users\Admin\AppData\Local\Temp\ServApi.exe
"C:\Users\Admin\AppData\Local\Temp\ServApi.exe"
1⤵
- Loads dropped DLL
- Suspicious use of SetThreadContext
- Suspicious behavior: MapViewOfSection
- Suspicious use of WriteProcessMemory
PID:1340

C:\Users\Admin\AppData\Local\Temp\ServApi.exe
"C:\Users\Admin\AppData\Local\Temp\ServApi.exe"
2⤵
PID:1712

MITRE ATT&CK Matrix ATT&CK v6

Initial Access

Execution

Persistence

Privilege Escalation

Defense Evasion

Credential Access

Discovery

System Information Discovery

T1082

Lateral Movement

Collection

Exfiltration

Command and Control

Impact

Replay Monitor

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Downloads

\Users\Admin\AppData\Local\Temp\nssA93B.tmp\System.dll
MD5
0063d48afe5a0cdc02833145667b6641

SHA1
e7eb614805d183ecb1127c62decb1a6be1b4f7a8

SHA256
ac9dfe3b35ea4b8932536ed7406c29a432976b685cc5322f94ef93df920fede7

SHA512
71cbbcaeb345e09306e368717ea0503fe8df485be2e95200febc61bcd8ba74fb4211cd263c232f148c0123f6c6f2e3fd4ea20bdecc4070f5208c35c6920240f0

Download Submit
memory/1340-2-0x0000000076691000-0x0000000076693000-memory.dmp

Filesize
8KB

Download
memory/1712-4-0x0000000040005EFA-mapping.dmp

Download
memory/1712-5-0x0000000040000000-0x0000000040009000-memory.dmp

Filesize
36KB

Download