Malicious PDF — malware analysis report

Static analysis result for SHA-256 b83408ddc2065ec6…

MALICIOUS

PDF

74.8 KB Created: 2021-09-22 15:54:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 479241e5cd3c40698bafe582086e98cf SHA-1: aa9e5315dbcddc5b88eba182da71b457c0dbfdca SHA-256: b83408ddc2065ec611e873c7a5a2dab695327af8be51a91cf7de8b0006008bd7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified the document as a link farm, with several URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious content. The embedded URLs, particularly those related to 'express vpn free trial apk download', indicate a lure for potentially unwanted software.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://www.marjojaspers.nl/ckfinder/userfiles/files/jilezilataluzukawat.pdf In PDF document text
    • http://gaziogluenerji.com/images_upload/files/47223844239.pdfIn PDF document text
    • http://coral-travel66.ru/admin/ckfinder/userfiles/files/10556963146.pdfIn PDF document text
    • http://webspace.mysdam.net/images/newsletter/files/duvuvewisokowasura.pdfIn PDF document text
    • https://pima-alarms.rs/slicice/file/41428141518.pdfIn PDF document text
    • http://romanasulcikova.cz/userfiles/towegopimopigimagat.pdfIn PDF document text
    • https://thietbixanh.net/uploads/files/80114506002.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/tq63o9k7j1gkum7j2bjuebp7t0/39139767197.pdfIn PDF document text
    • http://baozhaopharma.com/upload/files/dazexatolizetubadaxew.pdfIn PDF document text
    • https://iringmalaysia.com/ckfinder/userfiles/files/gugumijibidopofaxivi.pdfIn PDF document text
    • https://ihotel2b.com/upfiles/editor/files/37120454062.pdfIn PDF document text
    • https://alcoquimicos.com/ckfinder/userfiles/files/83355847779.pdfIn PDF document text
    • http://sea-cruise.ru/ckfinder/userfiles/files/wapobesoluxorenozugoru.pdfIn PDF document text
    • http://ddservice-bmw.pl/userfiles/file/jaginurupusavadekerif.pdfIn PDF document text
    • http://ajtoablakcentrum.com/_user/file/donimig.pdfIn PDF document text
    • https://brakos.it/file/92718896129.pdfIn PDF document text
    • http://kronospan-mofa-hungary.hu/editor_up/wujeresegi.pdfIn PDF document text
    • https://anitacalderon.com/ckfinder/userfiles/files/33543703769.pdfIn PDF document text
    • http://airelimpio.mx/img/editor/file/wasapijepetiru.pdfIn PDF document text
    • https://xn--espaoldetalca-lkb.cl/var/www/html/upload/file/gamotufonek.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/pntitth9pjaopi4ii7u2rellhn/16172110567.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16144ccd173011---kegabodizerudorevuz.pdfIn PDF document text
    • https://kalyna.ua/sites/default/files/userfiles/file/zoxinepulazujovumi.pdfIn PDF document text
    • https://imagebrandstudio.com/userfiles/file/bigumogokex.pdfIn PDF document text
    • http://website-design-company.in/dev3/damodar/ckfinder/core/connector/php/userfiles/files/winidivixiteramut.pdfIn PDF document text
    • https://aitalk.vn/upload/files/bepus.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=express+vpn+free+trial+apk+downloadPDF 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_off0000bf7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF7F 17104 bytes
SHA-256: 48bad5eaab528f12257924d021b7c49babf12fd95c87e569e53afaa55a0b793c
font_01_sfnt_off0000ec4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC4F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010466.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10466 10820 bytes
SHA-256: eba7e443271023775bfbc4f39907081965909e3d882fc23f0eea8efd76967859