Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8bda8a535268e8c…

MALICIOUS

PDF

79.0 KB Created: 2021-03-29 23:22:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: a3e602135ebb81b326f56838ebda57c8 SHA-1: 3fd80b2620e5f5f764b6679c8213c7f5558a5f65 SHA-256: d8bda8a535268e8c2a762dfe3638e1edd019b7e4f9186715b93d5de1d9158a49
226 Risk Score

Malware Insights

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

This PDF document contains numerous external links, many of which are algorithmically generated and point to disposable domains, indicating a link farm or SEO poisoning tactic. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The document body, though heavily obfuscated, contains text related to search queries, reinforcing the lure. No scripts were extracted, but the PDF structure itself facilitates the redirection to malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not 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.
  • 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://jacksth.ru/award?keyword=meaning+of+business+model+pdf PDF link annotation
    • https://cdn.sqhk.co/zexoribuj/jLhjN87/garezigafiwusixadalabaxim.pdfIn PDF document text
    • https://cdn.sqhk.co/loberutebe/d44YXQ7/shattered_pixel_dungeon_warrior_guide.pdfIn PDF document text
    • http://privateguardingserviceagainstdanger.site/royal_caribbean_cruise_out_of_galveston_todayv5haq.pdfIn PDF document text
    • http://sfhgfje5df.xyz/long_way_down_jason_reynolds_characters2u5mb.pdfIn PDF document text
    • http://espacecmb.xyz/balancing_equations_worksheet_1______na3po41aqv5.pdfIn PDF document text
    • http://futup.ru/multi_step_conversions_worksheetukblw.pdfIn PDF document text
    • https://cdn.sqhk.co/konidadelan/agePogf/ice_hockey_russia_liga_pro_tips.pdfIn PDF document text
    • https://cdn.sqhk.co/javomekoru/ihSkjIy/77691851925.pdfIn PDF document text
    • http://iclod.tech/simplex_maximization_method_of_linear_programmingk79k1.pdfIn PDF document text
    • http://jumpfs.space/peloton_exercise_bike_reviewe1wcy.pdfIn PDF document text
    • http://dvigatel.guru/standing_stones_ac_valhalla_gloucestershire46ond.pdfIn PDF document text
    • http://urott-hu.com/vevuksrvfm.pdfIn PDF document text
    • https://cdn.sqhk.co/sunawopi/ggjUie1/euro_truck_evolution_simulator_hack_apk_download.pdfIn PDF document text
    • https://cdn.sqhk.co/xizefonuma/deRgjgh/hungry_battle_blob_io_multiplayer_competitions.pdfIn PDF document text
    • https://cdn.sqhk.co/wezopexa/hae7Tih/ikea_bed_sheets_australia.pdfIn PDF document text
    • https://cdn.sqhk.co/fowurona/geXJpYC/zombie_survival_party_favors.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://ce2645ba-e89a-43d5-afff-5c0150757291.filesusr.com/ugd/c63dba_3e39e766e1c542b19a555ae28e2161a7.pdf?index=trueIn PDF document text
    • https://6cf80756-66c2-4d2e-b15d-ff1677cb7115.filesusr.com/ugd/2257e8_ad85b5cc605b448db7c9907007e68a08.pdf?index=trueIn PDF document text
    • https://f8d4b294-f952-4a11-85e8-0a3036f9bdaf.filesusr.com/ugd/ad8f3a_c42f4673283f4ff2945479b7aead6bc0.pdf?index=trueIn PDF document text
    • https://4cd5eafb-d261-4666-a528-29b55b1676c1.filesusr.com/ugd/8dde66_cd45b4aa21f244858f3b0aafc2558c8a.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f7e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7E8 5408 bytes
SHA-256: 16a70a44104883d46047e3268e91e667e574d1221981d5e75020e46ca1e0e3b2
font_01_sfnt_off00010a4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A4D 10888 bytes
SHA-256: b718278f39b1d2a232d2b5062e3369daae86d631475a005d58344f375149c0ef