Malicious PDF — malware analysis report

Static analysis result for SHA-256 f33a1bfa031388c7…

MALICIOUS

PDF

73.9 KB Created: 2021-06-06 23:29:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: aed91c19c35d559e3bdbfae6848aef96 SHA-1: 91937c9e0d5ceaed756a0b50484f19b613eb66ec SHA-256: f33a1bfa031388c74bdf409817ce8a7c7fb81c9cf225ca73d13c9e2a4a8db4b8
186 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many pointing to disposable hosting services, and is flagged by heuristics as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or SEO spam. The embedded URLs suggest an attempt to redirect users to malicious or spam content, potentially disguised as educational materials or certificates.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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 contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://ponafet.ru/123?utm_term=certificate+of+completion+word+document+template PDF link annotation
    • https://nubitewubol.weebly.com/uploads/1/3/4/3/134385952/5734750724e2d5d.pdfIn PDF document text
    • https://lilufegat.weebly.com/uploads/1/3/5/9/135965666/gixukutetarazop.pdfIn PDF document text
    • https://sovakevu.weebly.com/uploads/1/3/4/3/134341498/4704154.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4369764/normal_5fe02d8973f29.pdfIn PDF document text
    • https://devejibotabakap.weebly.com/uploads/1/3/4/7/134702496/1b538d.pdfIn PDF document text
    • https://dizegeduwawab.weebly.com/uploads/1/3/4/3/134374994/8553159.pdfIn PDF document text
    • https://jogapemufa.weebly.com/uploads/1/3/4/4/134492880/6d6a2ac6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4456686/normal_600fd169a1480.pdfIn PDF document text
    • https://fedalovojuxunod.weebly.com/uploads/1/3/0/7/130775560/sotapuxenukopi.pdfIn PDF document text
    • https://kitetunevoneg.weebly.com/uploads/1/3/4/7/134703129/vagem-rejolafipi-jutax.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/891b282c-ccdf-42ed-a323-94e6d7b33876/introduction_to_computer_vision.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/03a533c2-d1ad-4b86-a3e4-90133db7f0b4/50619895886.pdfIn PDF document text
    • http://zizovitunex.pbworks.com/w/file/fetch/144609429/exercises_on_phrases_and_clauses_for_class_8_with_answers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/12ccd9bd-8753-4ecc-921a-d0fcf101d484/31022920244.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cdf65465-0c37-4f85-8a79-2427ecad587e/16962940248.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8ae71c84-2873-4a31-97d0-2078945a9622/36735051197.pdfIn PDF document text
    • http://wenitat.pbworks.com/f/xofaxigojenu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2d874e1f-c992-435f-bc15-7a04cb565b1b/jivarijugaful.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6a218499-8f1e-4913-85c7-bb7b8670447d/the_watsons_go_to_birmingham_chapter_14_questions_and_answers.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_off0000e2f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2F0 5120 bytes
SHA-256: 615b9eaed9307e453a7907f0553638c0fc304248356d8a329cdf0b0103a65981
font_01_sfnt_off0000f455.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF455 10464 bytes
SHA-256: bd7885dcd3892d52032e4aa1206a0dd8cac6ce00eb9ac90ad56726da1f8df74b