Malicious PDF — malware analysis report

Static analysis result for SHA-256 3ef64b7a1642887b…

MALICIOUS

PDF

93.1 KB Created: 2021-09-16 02:38:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: f76a88e706839fa52375c837f0d70eb5 SHA-1: e2fef9ea036877815515f30ed290dc3a057351bb SHA-256: 3ef64b7a1642887b9fde2e3e118177d736bf33353e4bfcebec797c28c4a61824
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious intent. The embedded URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggest a link farm or phishing lure, aiming to redirect users to potentially harmful sites. No scripts were extracted, but the sheer number of embedded URLs points to a phishing or credential harvesting attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://amgaa.org/temp/files/16821327073.pdf In PDF document text
    • http://xn--ob0bjxt9h99icicrvkksa421cwwp7hiv4d6a.com/ckfinder/userfiles/files/zovenigalisivadudapor.pdfIn PDF document text
    • http://chaukitchen.com/uploads/files/mivomepedotujefomelaxula.pdfIn PDF document text
    • https://magyar-logyogyasz.hu/fileok/file/dafimudodeperitomejexad.pdfIn PDF document text
    • https://atlaskvartir.ua/data/uploads/files/fenupuduror.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/16132d63192af7---62184082860.pdfIn PDF document text
    • https://phuquiland.com/upload/files/zutajaxipudukinumu.pdfIn PDF document text
    • http://tranindo.com/Uploads/userfiles/files/58747838391.pdfIn PDF document text
    • https://namhunglogistic.vn/site/files/15711154092.pdfIn PDF document text
    • http://ryukatsu.com/userData/board/file/kusojawitulejave.pdfIn PDF document text
    • http://kup-vino.cz/web/ckfinder/userfiles/files/40304440278.pdfIn PDF document text
    • http://morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/161344d0a9e181---sisobetebuzaxa.pdfIn PDF document text
    • https://callmarkinvestments.com/callmark/files/webaxojotomotasenu.pdfIn PDF document text
    • http://harnettcountyhba.com/userfiles/file/13677043402.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/wetuvosajenonovi.pdfIn PDF document text
    • https://iwanbim.iwan.co/userfiles/files/98340353793.pdfIn PDF document text
    • http://rhoptik.cz/klienti/devel/sneznerolby.cz/ckfinder/userfiles/files/makebupepaniwidegibor.pdfIn PDF document text
    • https://totounited.com/contents/files/rexefo.pdfIn PDF document text
    • http://historico.uts.edu.co/portal/app/ckfinder/userfiles/files/wunilalejozumakiz.pdfIn PDF document text
    • https://amoslodge10-org.alljobsinliberia.com/ckfinder/userfiles/files/85723200291.pdfIn PDF document text
    • http://korealabels.com/ckfinder/userfiles/files/7248475465.pdfIn PDF document text
    • http://poornasreehomeoclinic.com/ckfinder/userfiles/files/76838687437.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=minecraft+mobestiary+freePDF link annotation
    • 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://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_off000104e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104E0 10700 bytes
SHA-256: f642625f64d827e0f56017a0242f243f0412185418d933e8462707cc881df759
font_01_sfnt_off00011d7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D7E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013590.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13590 19152 bytes
SHA-256: 144ccb225278ef04f18ad6af988d1489ac14c6f9c1ba9e2105102b7bceb52de2