Malicious PDF — malware analysis report

Static analysis result for SHA-256 f880489a42345a76…

MALICIOUS

PDF

99.5 KB Created: 2021-04-20 05:01:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 9b29254df9e3b61884016e5ffa9d735e SHA-1: 089c99bf0b74dbabb98aab55e447d72b2f76335f SHA-256: f880489a42345a76b3b480ebe22f53ed63d3ace3030263ee691ccd64c9f7f0ed
196 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to SEO-optimized content, suggesting a link farm or phishing lure. The primary URL, zajinet.ru, is identified as a redirector for phishing. ClamAV also detected this file as Pdf.Phishing.Trojan, reinforcing the phishing classification. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create PDFs from web content, aligning with the SEO link farm tactic.

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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://zajinet.ru/strik?utm_term=harrington+poker+cash+games+pdf PDF link annotation
    • http://znohist.site/86760772892zk8z1.pdfIn PDF document text
    • https://degevibuv.weebly.com/uploads/1/3/5/3/135316410/1241040.pdfIn PDF document text
    • http://20970907.net/fable_3_strategy_guide6chw4.pdfIn PDF document text
    • https://vuguzakinizole.weebly.com/uploads/1/3/4/4/134493236/tenixefufuwuxigu.pdfIn PDF document text
    • https://dawugagulinejud.weebly.com/uploads/1/3/4/3/134368664/vofowiwi-vimeden-fosukifagos.pdfIn PDF document text
    • https://numobokofe.weebly.com/uploads/1/3/4/5/134501802/jilewoj.pdfIn PDF document text
    • https://petomikerip.weebly.com/uploads/1/3/2/3/132303099/1136b4a.pdfIn PDF document text
    • http://fitit.space/antrenmanlarla_matematik_2_zmleri5y9vg.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/warapagefasovi/85694326668.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/14d185be-c4f9-4df7-b87a-b3a7384bc3ac/tofaporazi.pdfIn PDF document text
    • https://s3.amazonaws.com/bifadiwuwileji/mississippi_drivers_license_app.pdfIn PDF document text
    • https://s3.amazonaws.com/xakusineba/word_to_filehippo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/13e0346a-4445-4469-b8de-9e47fc0c5786/tugilipagowegip.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b599004d-745f-4324-b8df-ae699592f881/dosaxoti.pdfIn PDF document text
    • https://s3.amazonaws.com/xedewofuretujo/nebobegawepa.pdfIn PDF document text
    • https://s3.amazonaws.com/rejiner/midaxonufukusof.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f9de400c-254c-4f3b-8902-a2bfd6e06bc6/dantes_inferno_levels_of_hell_and_punishments.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/98f95cc4-ba50-46cb-b290-4c4502fed02f/2006_ford_e350_service_rsc_now.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0f443ee9-be68-4882-823c-77b005f448c2/interior_design_masters_degree_canada.pdfIn PDF document text
    • https://s3.amazonaws.com/kewuxejikiwe/bexigiwoziboveloguneg.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ce99059e-ec41-4121-a1ad-20e9166c50c8/data_structure_interview_questions_and_answers_for_freshers_free_download.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_off0001446e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1446E 5560 bytes
SHA-256: d4a35433fdd32fadf30e226ac050f73c44a8cf6ac189eb9154086d114c5ee754
font_01_sfnt_off0001572f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1572F 11980 bytes
SHA-256: 4a9f4e65aea740209b5c711141d570f36ae5fe30fb8bd0ee5d3bee7de976d8f4