Malicious PDF — malware analysis report

Static analysis result for SHA-256 81da4258b2df0990…

MALICIOUS

PDF

84.9 KB Created: 2021-06-16 20:33:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 91ac60dfc1b4b33734029fa5059b5251 SHA-1: ab2686e82010edf553c33aabfa10f1ae09393d62 SHA-256: 81da4258b2df0990f580a8de6970e33a0c14ca45afa611c85e6c5596e97613ad
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of these links and the overall structure point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://krisoc.ru/uplcv?utm_term=probability+exam+questions+and+answers+pdf PDF link annotation
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/lbqkg52urvr99rrbsm8eh663fk/repewopebodon.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080c7dd060d1.pdfIn PDF document text
    • http://ggmtc.net/userfiles/files/44284256851.pdfIn PDF document text
    • http://villaturri.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609ae6603fd35---59681994969.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160905d262699c---sedufunajugatanoxesik.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070ab24e5b43---33477289096.pdfIn PDF document text
    • https://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/034a095e9b418519da44e3a69744de80/nefowabivodamizejeza.pdfIn PDF document text
    • http://skncn.com/u/files/80911071388.pdfIn PDF document text
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094740d32224---38609561518.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16084cdcef036c---goniwigalugif.pdfIn PDF document text
    • https://valserve.in/web/k/main_admin/ckfinder/userfiles/files/9555758099.pdfIn PDF document text
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16083e355dc4ff---ludajepojotidopun.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607715863f9ab---33412816027.pdfIn PDF document text
    • http://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/0l4ajoq3347e0m317ta8atqc17/tabitavuwozi.pdfIn PDF document text
    • https://clickkedai.com/userfiles/file/xudemovudixisikuzuvipa.pdfIn PDF document text
    • http://bezagsecurity.cz/userfiles/sebetoboxaruvuluxo.pdfIn PDF document text
    • https://biodent.ro/m4fm_files/m4news/ck-uploads-files/95613444450.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c6159c78b3f---makopalota.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f41e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF41E 5716 bytes
SHA-256: d75bc9d76b55c3967177f2ac7307c72a23cda2f5c9604e7af65381455630446a
font_01_sfnt_off0001078f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1078F 11516 bytes
SHA-256: 15b6adba95e888174db31e44b8c9225c4c4a366efd95785bd9d3ba6bd6a1308b
font_02_sfnt_off00012f27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F27 16096 bytes
SHA-256: 9853a4a918762215dfcba51349555ff48d39e56332efe18e2f333ca30d8a5b61

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