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

Static analysis result for SHA-256 b1de3576310181db…

MALICIOUS

Office (OLE) / .XLSX

1.42 MB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: e0009b8647ceef59b53adaae1e3f45fb SHA-1: 08ccbd7a3cbe396977324b6c2dcb39bdfa8fadab SHA-256: b1de3576310181dbcc65b4f94db5dfd52d110c37262908365476370ce9dc211a
128 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution T1059.005 PowerShell T1204 User Execution

The critical heuristic firing for CVE_2017_0199 indicates that the sample is designed to exploit this vulnerability via a URL moniker, likely to download and execute a secondary payload from the specified URL. The embedded PDF also contains suspicious static findings, suggesting it may be part of a multi-stage attack. No VBA macros were found to contain executable statements, but the presence of the exploit and the embedded PDF strongly suggest a malicious intent.

Heuristics 3

  • 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.
    URL https://nucleo.ooo/SAyCdz
  • 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.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
7f506327609c082af1cd37dde23bc2c71a000f7d1ef530b6abb66775040a7673
vba-macro oletools.olevba.extract_macros (decoded VBA source) 1206 bytes
polyglot_child_pdf_off0006e200.pdf
58eb8ab005f563453d0bc97128443758c7d5d76a4c489b112959decf998a9315
polyglot-child-pdf Secondary PDF body inside ole container at offset 0x6E200 1038848 bytes