Malicious PDF — malware analysis report

Static analysis result for SHA-256 a40375be359e5713…

MALICIOUS

PDF

71.1 KB Created: 2021-04-16 16:53:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 28bc1763c1e9f40ef211ff47b3a4775a SHA-1: 4eaf654bf2bf62ff5c15f3ee3583b77594de5259 SHA-256: a40375be359e571385914378cd1222613e3e6d3d8572f4d42c910c15e2716566
126 Risk Score

Malware Insights

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

The file is a PDF that contains numerous embedded URLs, many of which point to unknown domains and are structured to appear as legitimate documents. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and embedded links suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/jebumimebugamoto.pdf In PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/fajabenofedutetigolexid.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/nuxikovevevugodir.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/4264017636.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/86303695333.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/35757612566.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/woluweweketasuzizolog.pdfIn PDF document text
    • http://www.birdlifebotswana.org.bw/sites/default/files/webform/sightings-sketches/beporu.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/87706268510.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/basolidigululaba.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/28941778760.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/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=why+does+a+small+engine+backfirePDF link annotation
    • https://printandmail.princeton.edu/system/files/webform/21338807989.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/46273532178.pdfIn PDF document text
    • https://www.vub.be/sites/vub/files/webform/43319512550.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/xafuzekimizitigemuseli.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_off0000d7f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7F1 5752 bytes
SHA-256: 42c4748a4ed913160e0961c84cc33b3b611e9a0e465af178b280bb9d6ccbd2e3
font_01_sfnt_off0000eb79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB79 10656 bytes
SHA-256: da543058d19e053e8bd11088e7950b97bf7694e6097c4c77376cc6d6dfb433c4