Malicious PDF — malware analysis report

Static analysis result for SHA-256 d6b5516300834ece…

MALICIOUS

PDF

73.9 KB Created: 2021-05-14 11:47:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 8d636b66f5b3f0263e23f90a43b3e0cb SHA-1: 73a2604d7d5690b6a5a09934006c7a36dabc35bd SHA-256: d6b5516300834ece6113320f94c2dd020b3c50020de1bffe63b85a2df43c4768
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, with one prominent URL pointing to 'zajinet.ru' and disguised with a 'ryobi+price+list' UTM parameter, suggesting a lure to trick users into clicking. The document body, though heavily obfuscated, contains metadata related to 'wkhtmltopdf' and a date, but the primary malicious indicators are the external links and the high-confidence detection scores.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://zajinet.ru/strik?utm_term=ryobi+price+list PDF link annotation
    • http://mazejofeg.mygamesonline.org/jubojojejaj.pdfIn PDF document text
    • https://cdn.sqhk.co/zesonixiv/i6jaH9I/ninja_assassin_costume_woman.pdfIn PDF document text
    • https://cdn.sqhk.co/totuzilexif/jhgfJE0/50004833863.pdfIn PDF document text
    • http://sell-toclick.online/divisibility_test_worksheets_free7vql2.pdfIn PDF document text
    • http://garobunatuxovi.scienceontheweb.net/77252170254.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383923/normal_606e515bce058.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450047/normal_602f45a0729c6.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4370076/normal_5ff81f8638b2f.pdfIn PDF document text
    • https://cdn.sqhk.co/jusupovexewa/jigiMUH/tiktok_views_booster_free.pdfIn PDF document text
    • http://avit0.cc/denefamui5l5y.pdfIn PDF document text
    • http://supsun-aero.com/pefolopireluvnem.pdfIn PDF document text
    • http://comforfemj.fun/how_to_fix_rust_on_my_jeepmvib1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384642/normal_60380f01df7c3.pdfIn PDF document text
    • https://cdn.sqhk.co/matijamaj/cggacVh/7596165192.pdfIn PDF document text
    • http://garanibukumom.scienceontheweb.net/99321868165.pdfIn PDF document text
    • https://cdn.sqhk.co/zapiseniw/v2gdpRz/bca_buyers_fees_list.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/9fe9e07a-1d42-4449-92a8-ebe3f7827f60/thompson_crafting_and_executing_strategy_22e.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/996ede89-8e6d-4136-8997-d9031a7627bc/what_are_the_four_general_principles_of_motivational_interviewing.pdfIn PDF document text
    • https://40ba1f7a-6e91-49bb-bbb8-dfbb40a2bc60.filesusr.com/ugd/22bf55_b727401bf3034fe08ebd7d66c98b1cb3.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/74b4ad95-fb79-4d9e-b14d-2b0f01e0f745/bigozetodumazuxe.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9b580eec-81cc-4fef-b7a3-0461cc592d86/what_is_the_life_events_stress_scale.pdfIn PDF document text
    • http://xotopusedewix.myartsonline.com/wububugivipoxafijezovu.pdfIn PDF document text
    • https://ddd59a73-be73-4575-bd7b-2e5900175f8b.filesusr.com/ugd/5dc0ef_0160ea7cbeb6486bbebd3430e2962f03.pdf?index=trueIn PDF document text
    • https://b6de9e3f-c562-4e05-b5ee-70895c8060ae.filesusr.com/ugd/3801ff_19a6060b3c0844b1a3ce411459cd24ad.pdf?index=trueIn PDF document text
    • https://d05b2b94-0af3-401c-a6ef-75d00d0b58ae.filesusr.com/ugd/3bca44_32d1d617ffcd4502897b492b687020d8.pdf?index=trueIn PDF document text
    • http://gajopule.myartsonline.com/used_honda_rebel_300_abs_for_sale_near_me.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_off0000e663.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE663 4964 bytes
SHA-256: a6bf2b1542071629b4566ab5d6a4c2a6c387c49d2b979b6acf20b0d0d1e8a135
font_01_sfnt_off0000f768.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF768 10228 bytes
SHA-256: eaeb6b6eff987f4780bf0cc6134293977d10fe373387dbb08446b707e3724600