Malicious Office (OLE) / .XLSX — malware analysis report

Static analysis result for SHA-256 8198d38eec5db0d3…

MALICIOUS

Office (OLE) / .XLSX

64.1 KB Created: 2021-12-16 23:53:43 Authoring application: Microsoft Excel
MD5: fb9cb7caf98d2f5383770c37e02c55c1 SHA-1: a5ecf18f04ad00f54dc4645c523aeca38b769c52 SHA-256: 8198d38eec5db0d3d520fbd8134884815417db8678630b611fee32b88e02950e
100 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic

The sample is an Excel file containing Excel 4.0 macros, specifically an Auto_Open macro. This macro is designed to execute a command that downloads a payload from a hardcoded URL. The document body also contains a lure to enable editing and content, which is a common tactic for macro-based malware.

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.
  • 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.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
c5aad075e50422dc1116ac70939d41e0371d46cf42a38ecf99b5202042a44db6		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 1374 bytes

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