Office (OOXML) malware analysis — malicious · c4a1b6a3206c8ec3

MALICIOUS

Office (OOXML)

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

MD5: 89d005099def1a84136c26fbde371735 SHA-1: f6ba400576902e4126d3f01236c7644d5f9d5f49 SHA-256: c4a1b6a3206c8ec33e216b08dbb5b54ee8202f05a731d3d5c91feb2eb146440e

260 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1059.001 PowerShell T1059.003 Windows Command Shell T1204.002 Malicious File

The OOXML document contains a Workbook_Open macro that executes obfuscated VBA code. This code references cmd.exe and PowerShell, and uses GetObject, indicating an attempt to download and execute a second-stage payload. The VBA code itself appears to be a Base64 decoder, suggesting it's used to deobfuscate malicious commands or scripts.

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` `5934006bece265e921441a60006711f37fc8249118e171d5a924976fc8ebece5`	vba-macro	oletools.olevba.extract_macros (decoded VBA source from OOXML)	36193 bytes
`vbaProject_00.bin` `a5623633ee769a5a3a301d7f5a12473a9b4d519889a8437eab8e5b397aed7bf7`	vba-project	OOXML VBA project: xl/vbaProject.bin	11776 bytes

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