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

Static analysis result for SHA-256 61c78d77df2247e7…

MALICIOUS

Office (OLE) / .XLS

80.7 KB Created: 1996-12-17 01:32:42 Authoring application: Microsoft Excel First seen: 2026-05-11
MD5: e86750f58003c0adc042b6330795cf29 SHA-1: bd5a32563d132be068a62ab001a2e30549fa47c5 SHA-256: 61c78d77df2247e74fddcde1ab1d50817797b9166a6192a91a1f67ce83bea37a
100 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is an Excel spreadsheet with a large amount of slack space, indicating potential obfuscation or appended malicious content. The document body contains text that mimics application forms for various permits, which is a common lure for phishing attacks aimed at collecting personal information. No scripts were extracted, and no specific IOCs were identified beyond the file itself.

Heuristics 2

  • Excel Index Array exploit — CVE-2008-3005 critical CVE likely CVE_2008_3005
    Legacy Excel workbook has the CVE-2008-3005 exploit shape: a compact BIFF8 FORMAT-index cluster paired with a normal XF table and a large unallocated OLE slack region used to stage the payload. The FORMAT pattern alone is not sufficient, so the rule requires the OLE slack payload-hiding context to keep false positives low.
  • OLE document has large unaccounted-for region high OLE_SLACK_ANOMALY
    OLE file is 82,666 bytes but its declared streams total only 21,308 bytes — 61,358 bytes (74%) live in unallocated sector slack. This is the canonical hiding place for pre-macro-era Office exploit payloads (XOR-encoded shellcode reached via a parser pointer-corruption bug in the document structure).