Malicious PDF — malware analysis report

Static analysis result for SHA-256 73fb61ff85219c99…

MALICIOUS

PDF

80.3 KB Created: 2021-03-27 19:33:55 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: f5b866f875be55d9ec53f82eebbb1831 SHA-1: c161271a3b2560ce732c59683e14c8a9230a12e0 SHA-256: 73fb61ff85219c9900a318d21b3b6e3897c1977f495c9ec5d8b7c54b9c53ea69
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many pointing to disposable hosting, suggesting a link farm or SEO manipulation tactic. The embedded document body, though heavily obfuscated, contains keywords related to academic topics and the authoring application 'wkhtmltopdf', which is often used to generate PDFs for SEO purposes. The primary attack pattern appears to be directing users to potentially malicious or misleading external websites.

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://lozipotod.ru/award?keyword=exercicios+sobre+poriferos+cnidarios+platelmintos+e+nematelmintos+pdf PDF link annotation
    • https://cdn.sqhk.co/zifuvifiweva/l8RLhhe/basic_cqb_tactics.pdfIn PDF document text
    • https://cdn.sqhk.co/pibavasedegi/lrhigis/ncaa_d2_soccer_championship_2019.pdfIn PDF document text
    • https://cdn.sqhk.co/wovupeni/jiZ6Tgh/road_rash_rider_mod_apk.pdfIn PDF document text
    • https://cdn.sqhk.co/zivuronufepu/igibsji/97360923373.pdfIn PDF document text
    • http://gikafowezogupij.mywebcommunity.org/20852855736.pdfIn PDF document text
    • http://dezimazokuxulil.mygamesonline.org/dark_souls_3_marry_anri_ending.pdfIn PDF document text
    • http://xamoxipuwizutux.scienceontheweb.net/16555393114.pdfIn PDF document text
    • http://nakekizedexu.getenjoyment.net/bpsc_pt_result_2020.pdfIn PDF document text
    • http://sopisafexuj.sportsontheweb.net/94805777138.pdfIn PDF document text
    • http://pedumerik.sportsontheweb.net/99996974312.pdfIn PDF document text
    • https://cdn.sqhk.co/bepeguvovori/jhgOieW/google_slides_templates_for_education.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://a5fc3680-5c08-4cda-bd6c-abaa3bdf25bc.filesusr.com/ugd/ea5d7b_a70734256f744530b43c19ad8030881d.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tirimofufemukat/57242492856.pdfIn PDF document text
    • https://f1fb087f-5d49-4061-aa02-230b108315d3.filesusr.com/ugd/645068_18f728cbf36241aab7a7af35427ba27b.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/fowikorejodi/bushnell_neo_ghost_golf_gps_for_sale.pdfIn PDF document text
    • https://3a00e800-a8eb-44ae-aafc-ae9aecab8e06.filesusr.com/ugd/1715bf_88c3a64de08a44a0a7331789aec0b7a3.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/farefasejikap/handy_stitch_handheld_sewing_machine_review.pdfIn PDF document text
    • http://polilofu.onlinewebshop.net/1999_buick_century_repair_manual.pdfIn PDF document text
    • https://8e8ef6ac-913c-489f-8395-c30730e7ba0a.filesusr.com/ugd/f39c52_149015ff431c4698a0299de65cce39e9.pdf?index=trueIn PDF document text
    • https://80b1f93a-fe74-4439-a81d-34814fa7a505.filesusr.com/ugd/e56fe2_4aabb4fcfe3646e4b95d56628f8e976f.pdf?index=trueIn 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_off0000eaa6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAA6 5252 bytes
SHA-256: 543b2b234f9434db481297386076ebf11a2bd6dd439176349d29e9dbc487b1c9
font_01_sfnt_off0000fc61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC61 12704 bytes
SHA-256: f4f7e93194470c42288b79c614c5c79359b2f4400778306f20ff919abba9f030
font_02_sfnt_off000122dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122DD 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378