Malicious PDF — malware analysis report

Static analysis result for SHA-256 d75e880ac23b6f81…

MALICIOUS

PDF

80.6 KB Created: 2021-04-08 16:19:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 4dce0ff79bb71b246f0d740b3ff6b731 SHA-1: 72435d8b35fcb0966b204c8c427aaac60a2b6028 SHA-256: d75e880ac23b6f819d7ab6a8b5edc8549a13fe3d025b07ad6d18489f6db64879
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 pointing to various domains, many of which are likely part of a link farm designed to obscure the ultimate destination. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM indicates a pattern of using disposable hosting for these links. While no scripts were explicitly extracted, the nature of the PDF and the embedded URLs suggest it's designed to redirect users to malicious sites, likely for phishing or to download further payloads.

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 https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/zizepuniket.pdf In PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/16831560309.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/58709767715.pdfIn PDF document text
    • http://www.birdlifebotswana.org.bw/sites/default/files/webform/sightings-sketches/12812059159.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/65810703597.pdfIn PDF document text
    • https://www.dgs-interparts.be/sites/default/files/7838369457.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/vinoku.pdfIn PDF document text
    • https://www.dgs-interparts.be/sites/default/files/57515461030.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/tirudekamevajoluzagobumi.pdfIn PDF document text
    • https://natsihwa.org.au/sites/default/files/webform/degajakuko.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/jowodudarazobipadumalo.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/86947183128.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/5308316073.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=acronis+true+image+2019+user+guide+pdfPDF link annotation
    • https://printandmail.princeton.edu/system/files/webform/67925993666.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ee50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE50 5796 bytes
SHA-256: 0805d68e5fa7b34673431dc03172d072549f5553c00518c012d628a7c470dc92
font_01_sfnt_off000101f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101F0 10872 bytes
SHA-256: 43a9b07816cb5897041a5c02d334ab82eeb88caf4b073163aa1d6edb680a59af
font_02_sfnt_off00012726.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12726 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378