Malicious PDF — malware analysis report

Static analysis result for SHA-256 23c18889fee33dbb…

MALICIOUS

PDF

84.6 KB Created: 2021-09-08 07:29:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 91461c3eb8500f5e0c7aa186aa0b0387 SHA-1: 02cd1bd1ef64d1405f49c347998ef2b5352ba11f SHA-256: 23c18889fee33dbbb6b2a50d989377dff339c1c548527fb1f2f61de18fedb4f8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, containing numerous URLs pointing to compromised websites and disposable hosting, likely intended to redirect users to malicious content. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically highlights the nature of these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/5fmaka26lt0ukbe0seviq33t27/gofinaretekenajedobif.pdf In PDF document text
    • http://ndc-group.ru/uploads/files/gufifugiximepetolo.pdfIn PDF document text
    • http://tydafa.com/dafa/uploadfiles/20210808045459.pdfIn PDF document text
    • https://www.burnat-provins.ch/ck/ckfinder/userfiles/files/62769465078.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/0pb4opevunnr1r2cpi41utktf5/72988741789.pdfIn PDF document text
    • https://hoatuoi360.vn/uploads/files/farusenabupax.pdfIn PDF document text
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/5aphkkoavgge80kkbar9iv0m3c/poxewudubixejopojofajut.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/92227f43270f0207bd5dfffe27d6be52/nizeropokabazisoj.pdfIn PDF document text
    • http://capitaldanceacademy.com/userfiles/files/66051035093.pdfIn PDF document text
    • https://penzionradvanice.cz/res/file/naxikazipin.pdfIn PDF document text
    • http://westleyden72reunion.com/clients/4/46/469dc9162705cbff2d1fbe132f144f37/File/88176804444.pdfIn PDF document text
    • https://chmelo.hu/sites/default/files/file/87261561822.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608abbbfe864d---15371412726.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160de9cfb15359---sinifumuxov.pdfIn PDF document text
    • http://www.verneteco.com/ckfinder/userfiles/files/vipavata.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160a21441df6b7---fawusigevilokalusazuruxab.pdfIn PDF document text
    • https://svetpoznaniyaonline.ru/wp-content/plugins/super-forms/uploads/php/files/451e29c5983aab04fa2d0ab585f3f210/gifuge.pdfIn PDF document text
    • http://vertracapital.com/uploads/files/98870354324.pdfIn PDF document text
    • http://fashionflutters.com/ckfinder/userfiles/files/vemaz.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b498270fd20---bivoweta.pdfIn PDF document text
    • http://execdentalclinic.com/uploads/ckfinder/userfiles/files/jokivirilo.pdfIn PDF document text
    • http://markasib.ru/ckfinder/userfiles/files/xodewuxovezisemaduwanor.pdfIn PDF document text
    • http://share-world.tw/userfiles/file/25238516054.pdfIn PDF document text
    • https://aldaserwis.pl/ckfinder/userfiles/files/mudopapelami.pdfIn PDF document text
    • https://marmarases.com/upload/ckfinder/files/rexajipozokisupunoputig.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=manual+gpsmap+64scPDF 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_off0000e1c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1C0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f9d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9D2 19304 bytes
SHA-256: ca3a61c521341e39159f7d24119dc367e8f92f373c8065ff71f396ebea2a280a
font_02_sfnt_off00012bb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BB8 10516 bytes
SHA-256: e550dbbe632b4423ff23dc258fc96cb464ae471123464590d19868a10a64847b