Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b82dc3511619080…

MALICIOUS

PDF

89.9 KB Created: 2021-07-08 06:45:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a094ab95fc255b13d791e12429e5b5cd SHA-1: cf29c8354a49f3758a04c93c388a3607017b4131 SHA-256: 1b82dc3511619080b65696bf82ca248f8d92ebf7252e68e3f40189288626e53e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains numerous external URLs, many pointing to compromised WordPress sites, 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 focus on external redirection, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://queure.ru/uplcv?utm_term=how+to+breed+a+sox+in+my+singing+monsters
    • https://nbcmedia.vn/ckfinder/userfiles/files/71077796320.pdf
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/1ef59ism7m43kl0dvmhbndj2a7/19817067825.pdf
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/12216a1f81dc9c8beda0e97fa0827005/sazor.pdf
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/4u626c8a0n29v493dco8gcqm29/69822301690.pdf
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a75994c2b5a---rirarozisosomilori.pdf
    • https://foxtailmag.net/wp-content/plugins/super-forms/uploads/php/files/003e7a6576d02069020934bd1c0c7019/68512063819.pdf
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/c3ph4nmp972b7e5e236aibatc3/bugadibitepibulezijiniwo.pdf
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d0f19c157a---kerizesofo.pdf
    • http://candientushinko.com/images/file/bumizoxakovunujegetupiv.pdf
    • https://youstore21.com/wp-content/plugins/super-forms/uploads/php/files/b3d98526d7d7548a8adc8df4a4b3d642/80909197102.pdf
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3b3a08d0a2---gujivibedajekefusob.pdf
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/160b711ca0c940---18944930637.pdf
    • http://alexanderkanevskyartgallery.com/clientMedia/file/8118873931.pdf
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/45fa8af31238ef5cf9e700cba2d6017e/50511071578.pdf
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/84ec02355b7f2adaaf563a99583ff9bd/97309755706.pdf
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/oap7hpjagrrecu9a9ud34k6e2g/kepujurerapodeb.pdf
    • http://brmhn.com/userfiles/file/20210529182207_d0j97f.pdf
    • http://www.buildingmalawi.com/images/uploaded/documents/15514767439.pdf
    • https://alatheir.com/atheirwsfiles/file/fojaju.pdf
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/ukb5ckffil9sgsp1j67pek3i73/40485354472.pdf
    • https://rhagro.com.mx/wp-content/plugins/super-forms/uploads/php/files/a63136a5790753f55215000412b4c822/sevulisom.pdf
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607185cfd368f---gomuwus.pdf
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16092c23d303a0---nilogemi.pdf
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160aad8b856585---zowipes.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f9dd.bin
9e12937ffab6e2a541c8b5ccf2d3ee901a16b73b98849f6ceab44e3396d2f6e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF9DD 10980 bytes
font_01_sfnt_off00011334.bin
a4fe30346b1b387a338666e68bc4c014eec29b6b49c0f3853b9a7329417c6636
pdf-font-stream PDF embedded font (sfnt) at offset 0x11334 17988 bytes
font_02_sfnt_off000141b8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x141B8 16792 bytes