Office (OLE) / .XLSX malware analysis — malicious · 7faefdf515b389b6

MALICIOUS

Office (OLE) / .XLSX

36.0 KB Created: 2020-11-25 10:40:21 Authoring application: Microsoft Excel

MD5: f82ce1ba5cac251b5d38e6e1e4938e46 SHA-1: 57623158432f3dc37f78ad0f8d9b921c15625203 SHA-256: 7faefdf515b389b61b0ee296379a4007a2887d23ee4cf920d349fb3e548a7cc1

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 defined name, which is a critical finding. This indicates the workbook is designed to automatically execute code upon opening. The presence of dangerous formula APIs like RUN further confirms the malicious intent to execute arbitrary commands. No specific IOCs like URLs or hashes were extracted, but the mechanism of execution is clear.

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` `300ca68422b0b60b3788291ec17910b26667dfcbd978e5f5d7dbd2b270ac60ab`	xlm-macro	oletools.olevba.extract_all_macros (XLM macro listing)	6598 bytes

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