Malicious PDF — malware analysis report

Static analysis result for SHA-256 b16ef331328fb5ea…

MALICIOUS

PDF

85.4 KB Created: 2021-09-19 22:19:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: ffa076a162fc52289a03d0b6ba773f51 SHA-1: 370416b3740f78eefd690c18dd60d119692de8ea SHA-256: b16ef331328fb5ea8c1404297fb2688fcb66d1413bef2018c30e462b4ed627f4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, specifically as a phishing trojan. It contains a large number of embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicates a deliberate effort to obscure the final destination and leverage potentially compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://nomylo.ru/uplcv?utm_term=no+sound+on+messenger+call PDF link annotation
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/eb0dbeacdb1d0890f0490590894a1b83/ralowolofo.pdfIn PDF document text
    • http://tv-sat.cz/userfiles/file/59371226471.pdfIn PDF document text
    • https://ibeguiristain.com/userfiles/files/11347846398.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f02b695c8d---21544337003.pdfIn PDF document text
    • https://www.rougeindigo.com/ckfinder/userfiles/files/bafigoxojabezirofux.pdfIn PDF document text
    • http://edwardfmcgintypa.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jepol.pdfIn PDF document text
    • https://glory-aqua.com/userfiles/file/sufumuzupujuperafuxik.pdfIn PDF document text
    • http://szolnokepul.hu/userfiles/file/wizalefidasaxu.pdfIn PDF document text
    • http://reanda.com/jingkelun/userfiles/files/20210901080249.pdfIn PDF document text
    • https://manage4.realtourvision.com/rtv/ckfinder/userfiles/images/files/48068723120.pdfIn PDF document text
    • https://delcinfo.ru/img/files/files/3498454890.pdfIn PDF document text
    • https://mimpishiosatu.com/contents/files/48214898224.pdfIn PDF document text
    • http://ezclasssites.com/var/wwww/dev-ezclasssites-com/data/files/fudelo.pdfIn PDF document text
    • http://clubselectionvoyages.com/images/file/61743904888.pdfIn PDF document text
    • https://optimuselearningschool.com/learning/site/images/uploadfiles/kopivarav.pdfIn PDF document text
    • http://qualityroofinnandsuites.com/nbloom/fckuploads/file/21834034362.pdfIn PDF document text
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/lijunufijevonibetutis.pdfIn PDF document text
    • http://stauarchitetti.eu/userfiles/files/wapubovixefikabakazupu.pdfIn PDF document text
    • http://dulwichtaxi.com/survey/userfiles/files/50634125428.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613da8d886b37---kevogivitazorikiwulaxejol.pdfIn PDF document text
    • https://yodishit.com/uploads/userfiles/file/50266508803.pdfIn PDF document text
    • https://ecoquimica.cl/dinamicos/uploads/file/56780248462.pdfIn 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://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_off0000e91c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE91C 10600 bytes
SHA-256: 41ff7cb5e35202ea7299b5f74519027f15c64aff5b7f8ac33bbd1789c5d402c7
font_01_sfnt_off00010116.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10116 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011928.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11928 18240 bytes
SHA-256: 63fd231c0b86d14392f5fed53c33ee91ef5f8c85250a44134599c643faac33cb