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

Static analysis result for SHA-256 efcc550dd777e23a…

MALICIOUS

Office (OLE) / .XLSX

424.5 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel First seen: 2023-07-19
MD5: a80b962767327854bbedf48dec54249c SHA-1: 4e9af38820e5963ad1f8d6b5c7520318038541f3 SHA-256: efcc550dd777e23a99efeb8fdc8f07fcd79d50001fe1c640c4a318717e771cc7
134 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1059.005 Visual Basic T1190 Exploit Public-Facing Application

The sample leverages the CVE-2017-0199 vulnerability, which is indicated by the OLE2Link/URL Moniker heuristic firing. This vulnerability allows the execution of remote code by downloading a secondary payload from the specified URL. The embedded PDF also contains suspicious findings, further supporting the malicious nature of the file. No VBA macros were found to contain executable statements, but the primary exploit mechanism is clear.

Heuristics 6

  • 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.
  • Secondary embedded PDF body has suspicious static findings critical 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.
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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.
  • 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 http://192.3.216.144/windows/windwindiwindiwndinwindnwindinw%23%23%23%23%23%23%23%23%23%23%23%23%23%23%23%23%23%23%23windiwisnwindiwnsiwndins.DOC

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
7f506327609c082af1cd37dde23bc2c71a000f7d1ef530b6abb66775040a7673
vba-macro oletools.olevba.extract_macros (decoded VBA source) 1206 bytes
stream_001_off00000960.bin
2998a126f4fa11ceb265371a5f7968ec18bc4692a32631a544232dc74040021f
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x960 252488 bytes
polyglot_child_pdf_off00001200.pdf
51808680bb52acf27ecf98ba4754ff88c859bf1f61e08f2fc35a26957d54eefb
polyglot-child-pdf Secondary PDF body inside ole container at offset 0x1200 430080 bytes
polyglot_child_pdf_off00024000.pdf
cfe0e5775d7b3a8dc4adf01f0c2346a72aff5dfc06fb70ec260f41b36464ce4b
polyglot-child-pdf Secondary PDF body inside ole container at offset 0x24000 287232 bytes
polyglot_child_pdf_off00046a00.pdf
cd568f97426175290b55b25090ed9ea14d10a24c9ce7a896f6a6c25a30796ece
polyglot-child-pdf Secondary PDF body inside ole container at offset 0x46A00 145408 bytes