Malicious PDF — malware analysis report

Static analysis result for SHA-256 87350830b300c2f7…

MALICIOUS

PDF

79.7 KB Created: 2021-03-31 06:21:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 2bcfb3c68b09659884378335e59c17cf SHA-1: a915094af2bfdde50089e0724a4126bd93e5fd6b SHA-256: 87350830b300c2f7a7cc5adde732452929238bd7ed4311707fe1fa12763f52a8
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristics identified it as a link farm hosted on disposable domains, with numerous external URIs pointing to potentially malicious content. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create PDF documents from web content, further supporting the link farm hypothesis.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://dugedepap.ru/strik?utm_term=new+fiddler+on+the+roof+movie+cast PDF link annotation
    • https://cdn.sqhk.co/subetudagoli/gfhhjeR/48962289955.pdfIn PDF document text
    • http://nubatevujonuw.mygamesonline.org/sap_bpc_460.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4383147/normal_5fca4bc19508a.pdfIn PDF document text
    • http://zanovekolasin.mywebcommunity.org/honda_ridgeline_transmission_fluid_change_interval.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490274/normal_6032c8764db36.pdfIn PDF document text
    • https://cdn.sqhk.co/tudenireso/iszzhhe/hollywood_movie_stickers.pdfIn PDF document text
    • https://cdn.sqhk.co/melivetipi/hbgdihp/9838649802.pdfIn PDF document text
    • https://cdn.sqhk.co/vovoritufi/iIwiaWh/pafuwulapu.pdfIn PDF document text
    • https://cdn.sqhk.co/vuwonesi/hgejgRl/dungeon_defenders_360.pdfIn PDF document text
    • https://cdn.sqhk.co/gixobujikelu/bjhhdhe/36275837895.pdfIn PDF document text
    • https://cdn.sqhk.co/kosibowo/ctaOhjI/best_new_alien_invasion_books.pdfIn PDF document text
    • https://cdn.sqhk.co/wijelukifap/Tjbq6he/stacking_colored_collect_blocks.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382962/normal_6063de2129ecf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481993/normal_606229332a6fd.pdfIn PDF document text
    • https://cdn.sqhk.co/sesudegaruta/jizihgf/27059998217.pdfIn PDF document text
    • http://xofofumireke.mypressonline.com/62680249778.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370541/normal_604cdfec3fddc.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/roware/google_chrome_beta_apkmirror.pdfIn PDF document text
    • https://s3.amazonaws.com/wanasuvedigo/muscle_mass_gain_diet_plan.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d1ce9e6b-dee6-4c4f-bb95-977e27299c36/pilopesekijek.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/74296fc6-0679-42ad-a0fe-50cb41086c47/general_electric_stove_xl44_parts.pdfIn PDF document text
    • http://tuwutexo.onlinewebshop.net/marriott_explore_rate_authorization_form.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2e71e36d-7524-4edd-aed9-ae9c6ef7dec6/jack_reacher_2_netflix.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7a9ad7fb-eb2c-4df4-9296-b9f1dff27d9c/59909875266.pdfIn PDF document text
    • https://s3.amazonaws.com/zemunomipazikez/goat_simulator_xbox_one_space_goat.pdfIn PDF document text
    • https://s3.amazonaws.com/babetafaperaxov/dovorejavuwotaxetako.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_off0000f85e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF85E 5380 bytes
SHA-256: ecf43a17fee302e473c090efa5f7a6a28f4ae36487004ebd40711b180b3bb9b2
font_01_sfnt_off00010a9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A9A 11340 bytes
SHA-256: 7c254342d917e2ded73aa8f2186718cbc45ce73d7462eefddfdcf9eb98e2a726