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

Static analysis result for SHA-256 786fb448f52ad1ab…

MALICIOUS

Office (OLE) / .XLSX

644.5 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel First seen: 2021-05-29
MD5: f2079b30faa57457ac9d4768a73d1588 SHA-1: 688cf34b8cf3e3aafccf95a5245425c0b11125ee SHA-256: 786fb448f52ad1aba291c24f1f554d6345f86906ecf6542fdf913afbaff4c7df
62 Risk Score

Malware Insights

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

The presence of Excel 4.0 macros (XLM) is a strong indicator of malicious intent, as this is an outdated and rarely used feature for legitimate purposes. The macros appear to be designed to download a file from one of the provided URLs, likely to execute a second-stage payload. The specific URLs are the highest priority IOCs for further investigation.

Heuristics 3

  • 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.
  • 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://eletrofrios.com/0cgEbnyc/ork.html Referenced by macro
    • https://sitka.in/rbWExNYu/ork.htmlReferenced by macro