Malicious PDF — malware analysis report

Static analysis result for SHA-256 f7a7c50868866360…

MALICIOUS

PDF

65.5 KB Created: 2021-04-08 17:50:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: aa21718aa6793baa8412254a6188469c SHA-1: 7499346baa4ea3a99398ad1f93c7e5f459683094 SHA-256: f7a7c508688663601da148b9edce9b574897cf489fe69deaa3afbba475d5ef79
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous embedded URLs, many pointing to disposable or unknown domains, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a malicious document designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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://www.osgeurope.com/sites/osg-corporate.dev/files/webform/nutuzisujobipusife.pdf In PDF document text
    • https://www.blplegal.com/sites/default/files/webform/3097059720.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/xaduxiwipel.pdfIn PDF document text
    • https://www.mainephilanthropy.org/sites/default/files/guvobirewuge.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/69174909787.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/21030689395.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/dadesiludidogujuta.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/mimixinaxeralowevowijut.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/58234525485.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/fenalop.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/dakatiwilu.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/dufovomajaxavekasodulep.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/bulurifabisiwotubavigivos.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=best+part+daniel+caesar+piano+sheet+music+pdfPDF link annotation
    • https://www.vub.be/sites/vub/files/webform/lijulur.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/67925993666.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/midari.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/53252105934.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/ninavixokamorul.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c476.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC476 5444 bytes
SHA-256: 9347fbd3923c98e394ea1adff0e9586bf39001176abe70deec0933a361429dbf
font_01_sfnt_off0000d6d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6D2 10200 bytes
SHA-256: bb8e8391c4ff20ec0bc13a3d7c37a5a2209c526118aeb2f8ed99fdda8b1ec6d7