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

Static analysis result for SHA-256 7c0777d387d12696…

MALICIOUS

Office (OLE) / .XLS

41.5 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 0c516f05ab99194f9cd190f6cb05e17d SHA-1: aeef12fe3c8ad4f364c1ca2053e0e74ea643bca0 SHA-256: 7c0777d387d12696e1e2c1acd23ffff712c0a1f69d41d2ae96d6d991a817a9af
140 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro-enabled spreadsheet. Heuristics indicate the presence of an Auto_Open macro, which is a common technique for executing malicious code upon opening the document. The macro sheet contains references to dangerous functions like RUN, suggesting it is designed to download and execute a second-stage payload. No specific family could be identified, but the technique is consistent with macro-based malware delivery.

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.

FilenameKindSourceSize
xlm_macros.txt
66f8625199b5c8adcf1811c92b0eac1ce3c671e24a2c18a6683304724168d223
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 7988 bytes