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

Static analysis result for SHA-256 28db3fdc87d166cc…

MALICIOUS

Office (OLE) / .EXI

53.0 KB Created: 1996-12-17 01:32:42 Authoring application: Microsoft Excel First seen: 2026-05-10
MD5: 69c5377c0f33cf1d7a559d368d9641b0 SHA-1: 719c07c36575e4b19138209ae0d6afaeb1943d06 SHA-256: 28db3fdc87d166cc18becc4e6318fc95b06fbc881c076bc4f5df408ba19bdded
100 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment

The file is an OLE document with a significant amount of slack space, indicating potential obfuscation or embedded malicious content. Although VBA macros could not be extracted due to an unsupported format, the document body presents itself as a series of application forms for permits. This suggests a social engineering lure, aiming to deceive the user into interacting with the document in a way that could lead to further compromise. The lack of extractable scripts or specific IOCs limits further analysis of the exact payload.

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 54,272 bytes but its declared streams total only 21,308 bytes — 32,964 bytes (61%) 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).