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

Static analysis result for SHA-256 57d8d4a52a8ae466…

MALICIOUS

Office (OLE) / .XLSX

1.02 MB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: f11d4f4a1c4b40a38a0d32a65b464853 SHA-1: 0bf28b871d1169fbbe565cf18b032f55f0479cae SHA-256: 57d8d4a52a8ae466a911161272b5416bff18784c91fcf631e193a2cbc4376920
170 Risk Score

Malware Insights

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

The critical heuristic firing for CVE-2017-0199 indicates that the OLE object attempts to use a URL moniker to load remote content. The embedded URL, https://short.ruksk.com/2ZPt3M?&chance=wealthy&guide=encouraging&president=aloof&conductor=cute&beverage, is highly suspicious and likely serves as a download location for a secondary payload. The presence of a polyglot child PDF with suspicious static findings further supports a malicious intent, potentially as a lure or part of the exploit chain.

Heuristics 5

  • OLE2Link / URL Moniker → remote loader — CVE-2017-0199 critical CVE likely CVE_2017_0199
    Document contains an embedded OLE link object whose URL Moniker points to a remote URL. When the host file is opened, Office follows the link, downloads the URL, and processes the response based on its Content-Type (HTA -> mshta.exe, RTF → Word, etc.) — the documented CVE-2017-0199 primitive. The URL extension is not a reliable filter; servers can return different payloads to Office's user agent.
  • ClamAV: Xls.Downloader.Trojan-aa0b8f388d8573cd-aa0b8f388d8573cd-9950439-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Trojan-aa0b8f388d8573cd-aa0b8f388d8573cd-9950439-0
  • Secondary embedded PDF body has suspicious static findings high POLYGLOT_CHILD_PDF_STATIC_TRIAGE
    A valid PDF body was found at a nonzero offset inside another container and its carved contents matched PDF exploit or lure heuristics. This catches polyglots where the top-level magic routes to ZIP/OLE while a PDF reader or downstream parser opens the hidden PDF payload.
  • VBA project contains no executable statements low OLE_VBA_MACROS
    Document contains a VBA project, but extracted modules only contain attributes/options/comments and no executable statements.
  • PDF paints image(s) but contains no text operators info PDF_IMAGE_ONLY_LURE
    PDF has 1 image XObject(s) and the content stream contains no text-emitting operators (BT/ET, Tj, TJ, ', ") in either raw bytes or decompressed streams — this is the screenshot-as-PDF pattern used to bypass text-based scanners and to deliver instructions purely through rendered pixels. It is informational unless paired with invisible links or risky URI context.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
382fc1344a2f0cf6eda18645d41def8d571debc6637bc7fe02a5c83715a51bef
vba-macro oletools.olevba.extract_macros (decoded VBA source) 2112 bytes
polyglot_child_pdf_off00000e00.pdf
20d6dddf490f6720d9391d3ae179924bfb899a828bd8d182d60130e91a379559
polyglot-child-pdf Secondary PDF body inside ole container at offset 0xE00 1068032 bytes