Office (OOXML) malware analysis — malicious · b4e8483fe4cda86d

MALICIOUS

Office (OOXML)

42.1 KB Created: 2021-06-22 12:43:05 UTC Authoring application: Microsoft Excel 16.0300

MD5: 6f920035af4b7c86461ec9adb52f4fc7 SHA-1: a3030ced7ec78e5cfb8a76990a312b6b2d9bff43 SHA-256: b4e8483fe4cda86dfd3d8ada698730b1a1e355776130e152981e12c6fa250429

260 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1059.001 PowerShell T1218.011 System Binary Proxy Execution: Rundll32 T1059.003 Windows Command Shell

The file contains VBA macros, including a Workbook_Open macro, which is a common technique for initial execution. The macros reference PowerShell and cmd.exe, and use GetObject to launch a Win32_Process, indicating an intent to execute arbitrary commands. The Decode64 function suggests obfuscated code, likely to download and execute a secondary payload.

Heuristics 6

PowerShell reference in VBA critical OLE_VBA_PS

PowerShell reference in VBA
VBA WMI Win32_Process launcher critical OLE_VBA_WMI_PROCESS_CREATE

VBA macro builds or references a WMI moniker for Win32_Process and invokes .Create to start a command. This is a high-confidence macro execution chain that often hides the WMI class name through string concatenation or helper functions.
Workbook_Open macro high OLE_VBA_WBOPEN

Workbook_Open macro
GetObject call high OLE_VBA_GETOBJ

GetObject call
cmd.exe reference in VBA high OLE_VBA_CMD

cmd.exe reference in VBA
VBA project inside OOXML medium OOXML_VBA

Document contains a VBA project — VBA macros present

Extracted artifacts 2

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`macros.bas` `663ee148abcfaf9dd3420a60cfb722ac2987861fb6b8392112ea95e4611619d6`	vba-macro	oletools.olevba.extract_macros (decoded VBA source from OOXML)	36009 bytes
`vbaProject_00.bin` `bfc37fff61c93bbce9da8c9d3148e0b52eecd579c4ddd05559d6d9e19cb82273`	vba-project	OOXML VBA project: xl/vbaProject.bin	11776 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.