Office (OLE) / .XLSX malware analysis — malicious · f976e7254c76cef0

MALICIOUS

Office (OLE) / .XLSX

36.0 KB Created: 2020-11-25 10:40:52 Authoring application: Microsoft Excel

MD5: 471f2ec66f8d4f4b3e5c48155eabd9a3 SHA-1: ef4836e5ebc593f55f350a1aa8f5b2aa9e8a22ed SHA-256: f976e7254c76cef0dbdd274e8cff3e62acbd3f03667630980af96919bb3c5489

140 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1059.001 PowerShell T1059.003 Windows Command Shell

The file contains Excel 4.0 macros, specifically an Auto_Open function, which is a critical indicator of malicious intent. The presence of dangerous formula APIs like RUN=0 within the Auto_Open macro suggests the execution of arbitrary code. While the exact payload is not directly visible, the structure strongly implies a downloader or initial execution stage for further malicious activity.

Heuristics 3

Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME

oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN

Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN

Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`xlm_macros.txt` `0fbf8b3700c04baaf50d8be28f47145dd0bd7fa62e6fafac8016838b2c39750d`	xlm-macro	oletools.olevba.extract_all_macros (XLM macro listing)	6399 bytes

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