Office (OLE) / .XLSX malware analysis — malicious · 5cbaa51de5417e93

MALICIOUS

Office (OLE) / .XLSX

35.5 KB Created: 2020-11-25 10:42:38 Authoring application: Microsoft Excel

MD5: 35359456679bd1ed73c32b3f71547fcc SHA-1: 0d76f66b98efeca7f593abc3a9e0abed88fe1ea7 SHA-256: 5cbaa51de5417e933eb367cefa646c5f56457f2b7ebee94a60be464f17e73ab1

140 Risk Score

Malware Insights

MITRE ATT&CK

T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding. This indicates an attempt to automatically execute code upon opening the workbook. The presence of dangerous formula APIs like RUN suggests the macro is designed to perform actions beyond standard spreadsheet operations, likely to download or execute a payload.

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` `67f1e6d6c2e965d60c66e2d1b5a5d7cd5b70605795d89131d6b99f9ccc1ffd1f`	xlm-macro	oletools.olevba.extract_all_macros (XLM macro listing)	6463 bytes

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