Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c5226512a5f99e0…

MALICIOUS

PDF

92.9 KB Created: 2021-04-05 14:57:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 686db5e1fecc523f9fa3b6c05cac638d SHA-1: dba166163af8f5bf0bca00bff7f16c80558d55f7 SHA-256: 4c5226512a5f99e04b6717c4f82971ed818ea7e1655448d650e47ed751b8bc22
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. The heuristics reveal it functions as a link farm, containing numerous external URLs designed to redirect users. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create PDFs from web content, further supporting the link farm hypothesis. The presence of many external links, some on disposable hosting, points towards phishing or SEO manipulation tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • 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 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://vilenefex.ru/award?keyword=criteria+used+in+canonization+of+the+new+testament+pdf PDF link annotation
    • https://cdn.sqhk.co/bepemuno/ifGidij/ludo_king_game_online_6_player.pdfIn PDF document text
    • http://prizinsta365.website/how_many_water_molecules_are_in_2.00_liters_of_waterh5r0f.pdfIn PDF document text
    • https://cdn.sqhk.co/devepogisog/hfBo3Ua/webuxi.pdfIn PDF document text
    • https://cdn.sqhk.co/zepipawetopi/Yjijb0C/firep.pdfIn PDF document text
    • http://pezuxedazof.iblogger.org/ripuwedopetovevo.pdfIn PDF document text
    • http://electorat.org/anandam_full_movie_tamilj9wnw.pdfIn PDF document text
    • https://cdn.sqhk.co/lofakekaf/Sijiihc/100_doors_horror_game.pdfIn PDF document text
    • http://vitrinachel.ru/lefezexotujopasidixajagebtv9l4.pdfIn PDF document text
    • http://piwokadewil.22web.org/classical_guitar_songs_everyone_should_know.pdfIn PDF document text
    • https://cdn.sqhk.co/pimidima/idiachh/metal_soldier_stickman_program.pdfIn PDF document text
    • http://goldenframecollision.com/jesus_coloring_pages_freeavyga.pdfIn PDF document text
    • https://cdn.sqhk.co/mixenezir/j7EjgKe/90480274174.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://f110cc6a-49d6-427c-9ab6-a3a4d323b004.filesusr.com/ugd/9e53d4_395417b365c94337aec0174f0cd020e4.pdf?index=trueIn PDF document text
    • http://sulorowanutabu.atwebpages.com/lunivuvi.pdfIn PDF document text
    • http://zaxawogaxema.epizy.com/43231892054.pdfIn PDF document text
    • https://e9593579-f51f-4dc6-af55-2543ab512b45.filesusr.com/ugd/37952c_06ce80ecdc4e48d3a6e93a1c94f8ee99.pdf?index=trueIn PDF document text
    • https://9e2b3e3a-6a02-4d3b-8ba9-5acc01041672.filesusr.com/ugd/66c878_2d70d1e2264a4cae8adb263a1d663122.pdf?index=trueIn PDF document text
    • http://dusameferadulo.onlinewebshop.net/le_verbe_etre_et_avoir.pdfIn PDF document text
    • https://9526c93a-d340-4dca-b5fd-2864ff0888c4.filesusr.com/ugd/4c3d6a_adbb58ca33bf43b98b7590e866fac771.pdf?index=trueIn PDF document text
    • http://nijomabip.epizy.com/xusavodeliwovidatijogoge.pdfIn PDF document text
    • https://3c1ad7ec-bfc7-452d-a92a-0d22078d3251.filesusr.com/ugd/c6e823_429484df661d460e9d46fbab256a1062.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_off00012ad7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AD7 5412 bytes
SHA-256: 7e29f49004f213788954b0b5ecb020c49cab4fe6e70d92a20e64d68e48fb5c83
font_01_sfnt_off00013d2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D2C 11652 bytes
SHA-256: 862730db5d10856c604d8674db050a4fcdb701419bf0159209241a3fc55256d9