buer | 9e746625abad522321067f546c40e8b26176ef5585bf3a45cb58ff758738f68c

General

Target

newbuer.exe
Size

111KB
MD5

4df84f8de8a5526f119c26518b529757
SHA1

42d281abeb10649bff097504f20e8fc2c8e85f5c
SHA256

9e746625abad522321067f546c40e8b26176ef5585bf3a45cb58ff758738f68c
SHA512

68cd6ce9eb7f01d7e6b2b2fff6dfdf981834168cb406a7d67df1f4c9d78b36b22689b03e408e3e68faf76d3bb4b0abd109024d4e2389258ea64a89f54e4a4b88

Score

10^/10

buer loader persistence

Malware Config

Extracted

Family

buer

C2

https://maldivosgrant.net/

https://jokenoiam.net/

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

description	ioc	Process
Set value (str)	\REGISTRY\USER\S-1-5-21-3341490333-719741536-2920803124-1000\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell = "explorer.exe, \"C:\\ProgramData\\RedTools\\networker.exe\""	networker.exe

Buer Loader 6 IoCs

Detects Buer loader in memory or disk.

resource	yara_rule
behavioral2/memory/4272-1-0x0000000040000000-0x000000004000C000-memory.dmp	buer
behavioral2/memory/4272-2-0x0000000040003467-mapping.dmp	buer
behavioral2/memory/4760-4-0x0000000002140000-0x000000000214C000-memory.dmp	buer
behavioral2/memory/4272-3-0x0000000040000000-0x000000004000C000-memory.dmp	buer
behavioral2/memory/836-11-0x0000000040003467-mapping.dmp	buer
behavioral2/memory/584-14-0x0000000002350000-0x000000000235C000-memory.dmp	buer

Executes dropped EXE 2 IoCs

pid	Process
584	networker.exe
836	networker.exe

Deletes itself 1 IoCs

pid	Process
836	networker.exe

Loads dropped DLL 2 IoCs

pid	Process
4760	newbuer.exe
584	networker.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

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

Suspicious use of SetThreadContext 2 IoCs

description	pid	Process	procid_target
PID 4760 set thread context of 4272	4760	newbuer.exe	78
PID 584 set thread context of 836	584	networker.exe	80

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

System Information Discovery
T1082

NSIS installer 6 IoCs

installer

resource	yara_rule
behavioral2/files/0x000300000001a2df-6.dat	nsis_installer_1
behavioral2/files/0x000300000001a2df-6.dat	nsis_installer_2
behavioral2/files/0x000300000001a2df-7.dat	nsis_installer_1
behavioral2/files/0x000300000001a2df-7.dat	nsis_installer_2
behavioral2/files/0x000300000001a2df-12.dat	nsis_installer_1
behavioral2/files/0x000300000001a2df-12.dat	nsis_installer_2

Suspicious behavior: EnumeratesProcesses 2 IoCs

pid	Process
836	networker.exe
836	networker.exe

Suspicious behavior: MapViewOfSection 2 IoCs

pid	Process
4760	newbuer.exe
584	networker.exe

Suspicious use of WriteProcessMemory 14 IoCs

description	pid	Process	procid_target
PID 4760 wrote to memory of 4272	4760	newbuer.exe	78
PID 4760 wrote to memory of 4272	4760	newbuer.exe	78
PID 4760 wrote to memory of 4272	4760	newbuer.exe	78
PID 4760 wrote to memory of 4272	4760	newbuer.exe	78
PID 4272 wrote to memory of 584	4272	newbuer.exe	79
PID 4272 wrote to memory of 584	4272	newbuer.exe	79
PID 4272 wrote to memory of 584	4272	newbuer.exe	79
PID 584 wrote to memory of 836	584	networker.exe	80
PID 584 wrote to memory of 836	584	networker.exe	80
PID 584 wrote to memory of 836	584	networker.exe	80
PID 584 wrote to memory of 836	584	networker.exe	80
PID 836 wrote to memory of 640	836	networker.exe	81
PID 836 wrote to memory of 640	836	networker.exe	81
PID 836 wrote to memory of 640	836	networker.exe	81

C:\Users\Admin\AppData\Local\Temp\newbuer.exe
"C:\Users\Admin\AppData\Local\Temp\newbuer.exe"
1⤵
- Loads dropped DLL
- Suspicious use of SetThreadContext
- Suspicious behavior: MapViewOfSection
- Suspicious use of WriteProcessMemory
PID:4760
- C:\Users\Admin\AppData\Local\Temp\newbuer.exe
  "C:\Users\Admin\AppData\Local\Temp\newbuer.exe"
  2⤵
  - Suspicious use of WriteProcessMemory
  PID:4272
- - C:\ProgramData\RedTools\networker.exe
    C:\ProgramData\RedTools\networker.exe "C:\Users\Admin\AppData\Local\Temp\newbuer.exe" ensgJJ
    3⤵
    - Executes dropped EXE
    - Loads dropped DLL
    - Suspicious use of SetThreadContext
    - Suspicious behavior: MapViewOfSection
    - Suspicious use of WriteProcessMemory
    PID:584
  - - C:\ProgramData\RedTools\networker.exe
      C:\ProgramData\RedTools\networker.exe "C:\Users\Admin\AppData\Local\Temp\newbuer.exe" ensgJJ
      4⤵
      Modifies WinLogon for persistence
      Executes dropped EXE
      Deletes itself
      Enumerates connected drives
      Suspicious behavior: EnumeratesProcesses
      Suspicious use of WriteProcessMemory
      PID:836
    - - C:\Windows\SysWOW64\secinit.exe
        
        C:\ProgramData\RedTools\networker.exe
        5⤵
        
        PID:640

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

Replay Monitor

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Downloads

memory/584-14-0x0000000002350000-0x000000000235C000-memory.dmp

Filesize
48KB

Download
memory/4272-3-0x0000000040000000-0x000000004000C000-memory.dmp

Filesize
48KB

Download
memory/4272-1-0x0000000040000000-0x000000004000C000-memory.dmp

Filesize
48KB

Download
memory/4760-4-0x0000000002140000-0x000000000214C000-memory.dmp

Filesize
48KB

Download

Analysis

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