Office (OOXML) malware analysis — malicious · a2f24071b3e0ad3f

MALICIOUS

Office (OOXML)

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

MD5: ef1e667536c17862ea3eb5d44fb1d90b SHA-1: 0faba37cb36b73f6e4f3679f790e3a5cba86e3f7 SHA-256: a2f24071b3e0ad3fbc0e5171de0a8f9bdd2b07ca2d98df7ab09d71d3fedf9fb8

260 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File T1105 Ingress Tool Transfer

The file contains VBA macros, specifically a Workbook_Open macro, which is a common technique for initial execution. The macros reference cmd.exe and PowerShell, and use WMI to launch a process, indicating an intent to download and execute a second-stage payload. The presence of a Base64 decoding function suggests obfuscation of malicious code or URLs.

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` `cd97d5dbf25ca5d5f67ef564703f12ead88d8d62514ef2925d2218a078b07b9b`	vba-macro	oletools.olevba.extract_macros (decoded VBA source from OOXML)	36393 bytes
`vbaProject_00.bin` `5cc1e4270f44a0aa31b00f1e4219ccbddd5f6d914984629b51d63b468f3fc370`	vba-project	OOXML VBA project: xl/vbaProject.bin	11776 bytes

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