Malicious PDF — malware analysis report

Static analysis result for SHA-256 35eb74d3a6883409…

MALICIOUS

PDF

87.2 KB Created: 2021-07-02 15:06:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 964b658d56b1a9d3887c93b23dea32b4 SHA-1: 68960f85f03058c82552e43cc702029d223b96ea SHA-256: 35eb74d3a6883409ddbce63a20b76fed355daca872f962d2e80da24c237b5388
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV confirming it as a phishing trojan. The file contains numerous links pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The primary attack pattern involves directing users to external, potentially compromised, URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://arhometutor.com/userfiles/file/dubutobixunakuxonedi.pdf In PDF document text
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/66df39f16dcf14c29bc7fd51e6508aff/kumegeb.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083cb131eb86---33259434704.pdfIn PDF document text
    • http://boekenwinkelindex.nl/images/uploads/sudapu.pdfIn PDF document text
    • https://kodcomputers.ro/2664/uploads/sevibejedupa.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/160ccacfc4ee3b---ketumavuvukewimotesoda.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609b95be7a15c---60047540718.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b2e3e111a15---nopugizazo.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/bucdt7tk0f51ifqgn4ac5g0jm4/79000635995.pdfIn PDF document text
    • http://zartmobilia.com/userfiles/file/20210619143433.pdfIn PDF document text
    • http://northwestpixie-bobs.com/clients/e/e1/e1941a3904c49320334fd90e0ed9e852/File/58869952707.pdfIn PDF document text
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/88f58b38012fe32b4c271b7e74ef5c19/33069715156.pdfIn PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcbac19f040---17144979698.pdfIn PDF document text
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/160834056032df---2814217742.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/lgovjleo20831q9s0ffisv9ar3/rexubutedof.pdfIn PDF document text
    • https://belgradenightlife.info/wp-content/plugins/super-forms/uploads/php/files/dov7rpk9ncaiaae2cs382m8ijm/nabapanatasodawefejij.pdfIn PDF document text
    • https://floridainvestment.cz/files/file/98882465410.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/0e024e513612f1b39ba3163320aa68fc/dowazurazakoxagugaz.pdfIn PDF document text
    • https://cungcapthitdetuoi.com/app/webroot/files/images/pages/files/tobuditetedemuka.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e383a4da92---zadawezofirememi.pdfIn PDF document text
    • http://zoncmswebsitebeheer.nl/files/editor/file/91674883469.pdfIn PDF document text
    • http://animationcoach.com/userfiles/file/31558773293.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160b4bedd1981b---weganemipazubi.pdfIn PDF document text
    • http://xtra360.net/campannas/file/93695007295.pdfIn PDF document text
    • https://jdrum-music.com/uploads/ckfiles/files/xobup.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/1608b1b1690359---sofelitotuwupekogizuma.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=guess+the+movie+solutionsPDF 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_off0000f322.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF322 10316 bytes
SHA-256: 4a04ef8be867512647ea4f2d947dc999d331ebc1b1eedcc927c3104d1b6167a3
font_01_sfnt_off00010a43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A43 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012255.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12255 17524 bytes
SHA-256: 656f719a04d8235fb42825187db3cc2edb298d5562a7db4070195af80640544a