Malicious PDF — malware analysis report

Static analysis result for SHA-256 77645dbbd5938323…

MALICIOUS

PDF

80.1 KB Created: 2021-04-14 14:55:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 10dfc51c390e4f029738fcad523f7cda SHA-1: c916895383872c742be9c86bf22f5954eb97feea SHA-256: 77645dbbd5938323e2dc54f588827a5bf3c3afc0ce2d88f9a7da7bc0f252ea30
184 Risk Score

Malware Insights

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

The PDF contains multiple embedded links, with at least one identified as a known malicious redirector. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and contains metadata suggesting it was generated by wkhtmltopdf, but the primary malicious activity is driven by the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://yafferge.ru/strik?utm_term=pioneer+vsx+523+receiver In PDF document text
    • https://cdn.sqhk.co/rudolikube/zkhbUjg/kujumovoraxafomuvo.pdfIn PDF document text
    • http://espaceclient-cmb.com/contract_addendum_form_meaning22syd.pdfIn PDF document text
    • https://cdn.sqhk.co/xixujipum/zhejhgp/the_speed_ninja.pdfIn PDF document text
    • http://sayseedokg.com/sonic_jr_breakfast_burrito_with_bacon_caloriesgt4hi.pdfIn PDF document text
    • https://cdn.sqhk.co/rewazexi/ghb8Mie/70275995137.pdfIn PDF document text
    • http://starconflict-game.ru/gamughsdpm.pdfIn PDF document text
    • https://cdn.sqhk.co/gitovera/iiJfghf/tolofizif.pdfIn PDF document text
    • http://zawukinaloluku.sportsontheweb.net/valejenapelex.pdfIn PDF document text
    • https://cdn.sqhk.co/noperizapewo/fHibDPc/japan_taxi_app_cash_payment.pdfIn PDF document text
    • http://7lessons.space/how_much_is_a_citizen_watch_batteryqs37w.pdfIn PDF document text
    • https://cdn.sqhk.co/dofewijoras/3jeiijh/game_wallpaper_hd_for_smartphone.pdfIn PDF document text
    • https://cdn.sqhk.co/vumivatuvi/dyDibIU/bts_dynamite_lyrics_wiki.pdfIn PDF document text
    • https://cdn.sqhk.co/gujuvizaja/UnEbggq/repid.pdfIn PDF document text
    • https://cdn.sqhk.co/terodekijur/hFbK4gd/thorax_mlp_age.pdfIn PDF document text
    • http://fontawesome.iohttp://fontawesome.io/license/In PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://vogapodidojuguf.myartsonline.com/advantages_of_parliamentary_system.pdfIn PDF document text
    • http://xowilewegiwo.myartsonline.com/o_reilly_fluent_python.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5bb7242c-65e2-4e3a-8605-56dc32138ec8/64215810639.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/84314451-1a11-44dc-b236-0f38a421e8e0/best_mechanical_engineering_schools_in_georgia.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7b299959-94b0-4232-9a60-718fb2bc2be0/37940274115.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e85aa849-fbdd-4eaf-9e6d-bd334062e8a6/can_praying_cure_depression.pdfIn PDF document text
    • http://ralirajuz.atwebpages.com/12584823305.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/316aea45-13d8-4cc2-b543-31839b4e997f/how_to_program_remote_to_philips_tv.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_off0000f070.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF070 1540 bytes
SHA-256: c1634b88d024ffa3df0e9e48774055d161dad072bce02dcf0d8163d62f2337b4
font_01_sfnt_off0000f84a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF84A 5100 bytes
SHA-256: 1fe452fe6ca90d0c8a2bbf3a383dae8df3a7bbabae559dafcf244b154c34d71e
font_02_sfnt_off000109cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109CC 11484 bytes
SHA-256: efb8b3a37a0f2a62871314b5cf79826e4576719b3e43a4846eecf592b7cfd33d