Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 4aa3856389a02291…

MALICIOUS

Office (OOXML)

2.66 MB Created: 2020-02-01 18:28:07 UTC Authoring application: Microsoft Excel 12.0000 First seen: 2021-03-01
MD5: ab8c2fb140776a0a5fbf2b17aab31bb3 SHA-1: 5e2751f9eada14145c8e9782f99901e5b2c750d7 SHA-256: 4aa3856389a02291003b00a443ec0918b3309e570fd18a3910634ce0701416e4
206 Risk Score

Heuristics 8

  • ClamAV: Xls.Dropper.Valyria-10030821-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Dropper.Valyria-10030821-0
  • Embedded Office object carries macros critical OFFICE_EMBEDDED_MACRO_OBJECT
    This document embeds a second Office file that itself contains a VBA macro project or an Excel 4.0 (XLM) macro sheet. Hiding a macro-bearing workbook or document inside another document — frequently under an obfuscated, non-standard part name — is a macro-smuggling technique that defeats scanners which only inspect the outer document's macro storage. No benign authoring workflow stages a hidden macro project this way.
  • VBA project inside OOXML medium 1 related finding OOXML_VBA
    Document contains a VBA project — VBA macros present
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Triggers on the COMBINATION of two tokens co-occurring in the same compiled VBA/cache stream: an auto-execution entry point (Auto_Open / AutoOpen / Document_Open / Workbook_Open / Auto_Close / AutoClose) AND a shell/download/object-execution token (Shell, CreateObject, GetObject, PowerShell, cmd.exe, URLDownloadToFile, WinHttp, XMLHTTP, ADODB.Stream, ShellExecute, ExecuteExcel4Macro). Neither token alone fires it — it is the pairing that flags p-code-only or source-extraction-failure macro documents where the visible VBA source is unavailable. The matched tokens are named in the detail line below.
  • Embedded OLE object medium OOXML_OLE_OBJECT
    Document contains an embedded OLE object
  • Large OOXML part skipped info SCAN_INCOMPLETE
    One or more high-value OOXML parts exceeded the scanner's per-entry size cap and may not have been fully inspected.
  • Payload URL recovered from embedded OLE object (1 URL) info OOXML_EMBEDDED_OBJECT_URL
    An embedded OLE object (xl/word/ppt embeddings) carries a next-stage download URL in its Ole10Native/Package stream — stored literally (incl. UTF-16) or base64-encoded — which the package-level URL sweep does not see. Surfaced as an IOC; self-validating (only real payload hosts).
  • 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://www.top3petproducts.in/Diskfejle.exe In document text (OOXML body / shared strings)