Office (OLE) / .XLSX malware analysis — malicious · 3c346cf00ccddbd0

MALICIOUS

Office (OLE) / .XLSX

36.0 KB Created: 2020-11-27 11:40:11 Authoring application: Microsoft Excel

MD5: d03995d5dc0a317f111ba13d422b0b6f SHA-1: 9183f4812c1617562d44a4ca8d4c38f4f2b153dc SHA-256: 3c346cf00ccddbd0e74414dc915f8dfbe4b0ebf5abc858ee32effdc6c11d31be

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 indicator of malicious intent. The presence of dangerous formula APIs like RUN in the Auto_Open macro suggests the execution of arbitrary commands. While the exact commands are not fully detailed in the provided script excerpt, the mechanism points to a macro-based execution of potentially harmful code.

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` `d6154cefb48f91f9c12f4f495f7730d6fbf81e39f09581f7ddef8282dff2ffc4`	xlm-macro	oletools.olevba.extract_all_macros (XLM macro listing)	6916 bytes

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