Malicious PDF — malware analysis report

Static analysis result for SHA-256 24c0542a9389c63d…

MALICIOUS

PDF

68.3 KB Created: 2021-04-10 13:49:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: f2bf10e5f130dab32cf76ca7f505ac69 SHA-1: 3a94a49c40cab8a95f5f0d81d2d513c6d8d0dc9c SHA-256: 24c0542a9389c63da598eed9136c23988c874fc76f9614b19d6365afad6e68b7
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, with one pointing to a suspicious domain that is part of a link farm. Although no scripts were explicitly extracted, the PDF structure and the presence of external URIs suggest an attempt to redirect the user to a malicious site, likely for phishing or to download a secondary payload.

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.ofalloncasting.com/sites/default/files/webform/taxebuvokorutupimapo.pdf In PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/kanuvanirarotugawabu.pdfIn PDF document text
    • http://www.birdlifebotswana.org.bw/sites/default/files/webform/sightings-sketches/lewuxevibonotokezesa.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/sidetarebuw.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/11252708720.pdfIn PDF document text
    • https://www.dgs-interparts.be/sites/default/files/muvok.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/bunovodedodasu.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/42282539280.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/vetasitumuwogemukuruv.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/palepipob.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/25507329945.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/69309865186.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/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=les+sons+invers%25C3%25A9s+ce2PDF link annotation
    • https://printandmail.princeton.edu/system/files/webform/zixulupuritijidegebi.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/bejugejotofetuxiw.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_off0000cd42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD42 4828 bytes
SHA-256: 0c7a3a10c9ba68ee63b890153ca3cdb6f1e36fd029a1bae751fede58761569c7
font_01_sfnt_off0000dd84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD84 11696 bytes
SHA-256: 047176592b4f24ed6f96e191619276022dd493ed967beb5ec21362ca89bcbb84