Malicious PDF — malware analysis report

Static analysis result for SHA-256 31cafca82ddca199…

MALICIOUS

PDF

68.1 KB Created: 2021-04-25 09:48:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 67387067672dad9e28930f7f18205b4e SHA-1: 2afd6439f9cfaa31f03c673eb0dc169ede305254 SHA-256: 31cafca82ddca199ad73f3bc9cfc342ffd48b7f060942b564b8892c71df38f1c
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to disposable domains or are structured as link farms, indicating a phishing or redirection attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with common phishing lures.

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/tafunowusovuna.pdf In PDF document text
    • https://www.jwico.com/sites/default/files/webform/71926652616.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/fezijorimofilafomifum.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/95859103094.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/42282539280.pdfIn PDF document text
    • https://web.liderpapel.com/sites/default/files/webform/xikamiwaboloz.pdfIn PDF document text
    • https://www.dgs-interparts.be/sites/default/files/41094691834.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/55418097166.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/dizage.pdfIn PDF document text
    • https://architecturaldesigninc.com/sites/default/files/56675633315.pdfIn PDF document text
    • https://www.visitsavannah.com/sites/default/files/webform/mubojezelu.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/zMnd8XtcwSM/uplcv?utm_term=is+there+a+third+book+in+the+kingkiller+chroniclesPDF link annotation
    • https://lib.asu.edu/system/files/webform/liwubuwivak.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/94207829768.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/libovonudipiguriteg.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_off0000cc6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC6A 5344 bytes
SHA-256: ea1588307dd1a5093fee00ee92d4fa72ce283d9dffcd32018da103617c4336be
font_01_sfnt_off0000de8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE8B 10572 bytes
SHA-256: d0853f716ec851e1440445602d61c9df7b129eaf061f11926b3c49089b975f84