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

Static analysis result for SHA-256 b8441c2b7a84d840…

MALICIOUS

Office (OLE) / .XLS

525.5 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel First seen: 2021-05-26
MD5: 379ac4a7c703382a4794eb4fd20f950e SHA-1: 0eba5269e2e6b04a9efee4ff6901519ca16ce8f6 SHA-256: b8441c2b7a84d84038c9441b19905bb9dad5e15e860e5b7ffb98284709cfac34
142 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 Malicious File

The presence of an Excel 4.0 (XLM) macro sheet and a heuristic indicating a lure to enable macros strongly suggests malicious intent. The embedded URLs likely point to payloads or further stages of infection. The document body contains obfuscated strings that appear to be related to downloading and executing files, possibly via rundll32.

Heuristics 5

  • XLM Auto_Open workbook with payload URL or enable-content lure critical OLE_XLM_AUTOOPEN_PAYLOAD_LURE
    Workbook contains an Excel 4.0 macro sheet with Auto_Open / Auto_Close and also exposes a payload URL or enable-content lure in the OLE bytes. This combination is a high-confidence XLM downloader/social-engineering pattern even when formula recovery cannot decode the full macro chain.
  • Excel 4.0 (XLM) macro sheet uses dangerous capability functions high OLE_XLM_DANGEROUS_FN_STATIC
    Workbook contains an Excel 4.0 macro sheet whose formulas reference two or more dangerous capability functions (e.g. CALL into a Win32 API such as URLDownloadToFile, EXEC to launch a process, REGISTER an external DLL procedure, or FWRITE/FOPEN to drop a file) with an Auto_Open / Auto_Close auto-execution name. This is the canonical XLM downloader/dropper shape and is recovered directly from the BIFF records, so it fires even when the full macro chain cannot be deobfuscated.
  • 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
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://aravindanavada.com/AHt5r3T0VSlq/solo.html In document text (OLE body)
    • https://mrcrgroup.com/sOyQynNJYBY/solo.htmlIn document text (OLE body)