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

Static analysis result for SHA-256 1856cb4989e6595c…

MALICIOUS

Office (OLE) / .XLS

1.68 MB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 4166ea56dfa04503f9a1cda461ab042f SHA-1: 7c57eb4d8594498948226b3d65eada7a432af0a2 SHA-256: 1856cb4989e6595cc59062b753fabf80b09edb958e77022fc11e4f0b05340688
132 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.005 Visual Basic

The sample is an Excel file that leverages the OLE2Link vulnerability (CVE-2017-0199) to download and execute a secondary payload from the URL 'https://link.takusuki.com/1xW23M'. The presence of VBA macros, though not containing executable statements directly, is typical for this type of exploit. The embedded PDF also shows suspicious static findings, further indicating malicious intent.

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.
  • 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.
  • 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://link.takusuki.com/1xW23M
    • https://wwww.microsoft.com0
    • http://schemas.openxmlformats.org/drawingml/2006/main
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/pdf/1.3/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • https://docs.microsoft.com/typography/abouthttp://lucasfonts.comMicrosoft
    • http://en.wikipedia.org/wiki/MIT_License
    • http://crl.microsoft.com/pki/crl/products/MicCodSigPCA_2010-07-06.crl0Z
    • http://www.microsoft.com/pki/certs/MicCodSigPCA_2010-07-06.crt0
    • http://crl.microsoft.com/pki/crl/products/MicRooCerAut_2010-06-23.crl0Z
    • http://www.microsoft.com/pki/certs/MicRooCerAut_2010-06-23.crt0��
    • http://www.microsoft.com/PKI/docs/CPS/default.htm0@
    • http://crl.microsoft.com/pki/crl/products/MicTimStaPCA_2010-07-01.crl0Z
    • http://www.microsoft.com/pki/certs/MicTimStaPCA_2010-07-01.crt0
    • http://www.microsoft.com/pkiops/crl/Microsoft%20Time-Stamp%20PCA%202010(1).crl0l
    • http://www.microsoft.com/pkiops/certs/Microsoft%20Time-Stamp%20PCA%202010(1).crt0
    • http://www.microsoft.com/pkiops/Docs/Repository.htm0
    • http://www.microsoft.com/pki/certs/MicRooCerAut_2010-06-23.crt0

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_014_off0003f52b.bin
b0a7e7055d5b66edffe76c7b1f32ec80318d696df6181f1536f27aa69517872f
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x3F52B 566620 bytes
stream_015_off0006f1fe.bin
0d5715bfb4def94d644e408c5ed714ea2ac557b061d036e7fdcf0a2bf1c990e2
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x6F1FE 398152 bytes
font_02_sfnt_off000882ce.bin
ff37b045be3591e8cfbfa76f5dec51bee78deccafa1dc391d1edb36502c7f815
pdf-font-stream PDF embedded font (sfnt) at offset 0x882CE 346068 bytes
polyglot_child_pdf_off000b0600.pdf
00d755d9fe2f4567702bd3f9147859b0429b596f14e7229399d8a1dc8856bf66
polyglot-child-pdf Secondary PDF body inside ole container at offset 0xB0600 1036800 bytes