buer | 45cc417aeb30d7aaba675077c10f70d66ee9b1b8b4820f0469221f0a87fe9545

General

Target

Invoice.xlsb
Size

155KB
MD5

18cb83fa82fb14788d5a1cbafcd9bb28
SHA1

4b61151831eedeb225166c30c2e2b555c9e5b5d0
SHA256

45cc417aeb30d7aaba675077c10f70d66ee9b1b8b4820f0469221f0a87fe9545
SHA512

123acdaeb7baeb1bfe5284a70d920f692ff97927fe05cbbf56b029c93684aea5429c7e619a8a3ea2e55136d8398777f0e0b134cfe27e61b92acda0acf3ec5b4e

Score

10^/10

buer loader

Malware Config

Extracted

Family

buer

C2

softwareconsbank.com

Signatures

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

Buer Loader 3 IoCs

Detects Buer loader in memory or disk.

resource	yara_rule
behavioral1/memory/1880-8-0x0000000040000000-0x0000000040009000-memory.dmp	buer
behavioral1/memory/1880-9-0x0000000040005DA8-mapping.dmp	buer
behavioral1/memory/1880-11-0x0000000040000000-0x0000000040009000-memory.dmp	buer

Executes dropped EXE 2 IoCs

pid	Process
1072	spoolv.exe
1880	spoolv.exe

Loads dropped DLL 2 IoCs

pid	Process
1832	EXCEL.EXE
1072	spoolv.exe

Suspicious use of SetThreadContext 1 IoCs

description	pid	Process	procid_target
PID 1072 set thread context of 1880	1072	spoolv.exe	33

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

System Information Discovery
T1082

NSIS installer 8 IoCs

installer

resource	yara_rule
behavioral1/files/0x00030000000130da-3.dat	nsis_installer_1
behavioral1/files/0x00030000000130da-3.dat	nsis_installer_2
behavioral1/files/0x00030000000130da-5.dat	nsis_installer_1
behavioral1/files/0x00030000000130da-5.dat	nsis_installer_2
behavioral1/files/0x00030000000130da-6.dat	nsis_installer_1
behavioral1/files/0x00030000000130da-6.dat	nsis_installer_2
behavioral1/files/0x00030000000130da-10.dat	nsis_installer_1
behavioral1/files/0x00030000000130da-10.dat	nsis_installer_2

Enumerates system info in registry 2 TTPs 1 IoCs

Query Registry

T1012

System Information Discovery

T1082

description	ioc	Process
Key opened	\REGISTRY\MACHINE\Hardware\Description\System\FloatingPointProcessor	EXCEL.EXE

Modifies Internet Explorer settings 1 TTPs 9 IoCs

adware spyware

Modify Registry

T1112

description	ioc	Process
Set value (int)	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\MenuExt\Se&nd to OneNote\Contexts = "55"	EXCEL.EXE
Key created	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\MenuExt\E&xport to Microsoft Excel	EXCEL.EXE
Set value (int)	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\MenuExt\E&xport to Microsoft Excel\Contexts = "1"	EXCEL.EXE
Set value (str)	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\Toolbar\ShowDiscussionButton = "Yes"	EXCEL.EXE
Key created	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\MenuExt	EXCEL.EXE
Key created	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\MenuExt\Se&nd to OneNote	EXCEL.EXE
Set value (str)	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\MenuExt\Se&nd to OneNote\ = "res://C:\\PROGRA~2\\MICROS~1\\Office14\\ONBttnIE.dll/105"	EXCEL.EXE
Set value (str)	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\MenuExt\E&xport to Microsoft Excel\ = "res://C:\\PROGRA~2\\MICROS~1\\Office14\\EXCEL.EXE/3000"	EXCEL.EXE
Key created	\REGISTRY\USER\S-1-5-21-3825035466-2522850611-591511364-1000\Software\Microsoft\Internet Explorer\Toolbar	EXCEL.EXE

Suspicious behavior: AddClipboardFormatListener 1 IoCs

pid	Process
1832	EXCEL.EXE

Suspicious behavior: MapViewOfSection 1 IoCs

pid	Process
1072	spoolv.exe

Suspicious use of SetWindowsHookEx 3 IoCs

pid	Process
1832	EXCEL.EXE
1832	EXCEL.EXE
1832	EXCEL.EXE

Suspicious use of WriteProcessMemory 9 IoCs

description	pid	Process	procid_target
PID 1832 wrote to memory of 1072	1832	EXCEL.EXE	31
PID 1832 wrote to memory of 1072	1832	EXCEL.EXE	31
PID 1832 wrote to memory of 1072	1832	EXCEL.EXE	31
PID 1832 wrote to memory of 1072	1832	EXCEL.EXE	31
PID 1072 wrote to memory of 1880	1072	spoolv.exe	33
PID 1072 wrote to memory of 1880	1072	spoolv.exe	33
PID 1072 wrote to memory of 1880	1072	spoolv.exe	33
PID 1072 wrote to memory of 1880	1072	spoolv.exe	33
PID 1072 wrote to memory of 1880	1072	spoolv.exe	33

C:\Program Files (x86)\Microsoft Office\Office14\EXCEL.EXE
"C:\Program Files (x86)\Microsoft Office\Office14\EXCEL.EXE" /dde C:\Users\Admin\AppData\Local\Temp\Invoice.xlsb
1⤵
- Loads dropped DLL
- Enumerates system info in registry
- Modifies Internet Explorer settings
- Suspicious behavior: AddClipboardFormatListener
- Suspicious use of SetWindowsHookEx
- Suspicious use of WriteProcessMemory
PID:1832
- C:\GSEER\GefeDFpa\spoolv.exe
  "C:\GSEER\GefeDFpa\spoolv.exe"
  2⤵
  - Executes dropped EXE
  - Loads dropped DLL
  - Suspicious use of SetThreadContext
  - Suspicious behavior: MapViewOfSection
  - Suspicious use of WriteProcessMemory
  PID:1072
- - C:\GSEER\GefeDFpa\spoolv.exe
    "C:\GSEER\GefeDFpa\spoolv.exe"
    3⤵
    - Executes dropped EXE
    PID:1880

Network

MITRE ATT&CK Enterprise v6

Initial Access

Execution

Persistence

Privilege Escalation

Defense Evasion

Modify Registry

1

T1112

Credential Access

Discovery

Query Registry

1

T1012

System Information Discovery

2

T1082

Lateral Movement

Collection

Command and Control

Exfiltration

Impact

Replay Monitor

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Downloads

memory/1648-2-0x000007FEF5D50000-0x000007FEF5FCA000-memory.dmp

Filesize
2.5MB

Download
memory/1832-13-0x0000000001E40000-0x0000000001E41000-memory.dmp

Filesize
4KB

Download
memory/1880-8-0x0000000040000000-0x0000000040009000-memory.dmp

Filesize
36KB

Download
memory/1880-11-0x0000000040000000-0x0000000040009000-memory.dmp

Filesize
36KB

Download

Analysis

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