Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc74d56100af23e9…

MALICIOUS

PDF

86.7 KB Created: 2021-06-26 02:02:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e61554a249560ccd5727f2a17228449c SHA-1: 21e5c679483e7b9c8ac7488b274ab9ab6b79c5db SHA-256: bc74d56100af23e9e12bca805aab5ec57bfa2aa5f2189f500b44223d73027dea
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs point to compromised WordPress sites and other disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be non-readable content from the wkhtmltopdf tool, rather than user-facing text.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://medvor.ru/uplcv?utm_term=this+is+a
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/160b459b229ccb---3053400713.pdf
    • https://reflexlighting.com/wp-content/plugins/super-forms/uploads/php/files/d48b7f3b12f2f1a1e3b28efa65866404/70188089533.pdf
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/16073c05f0335e---42101057514.pdf
    • http://redwoodpwr.com/wp-content/plugins/super-forms/uploads/php/files/85fqvd2jbbt97jii230jp6o0s0/rofexodobirur.pdf
    • https://amenagementsoleil.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089755e02232---90371560311.pdf
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/1afb7df3ad50869610c84f72790a61d0/danowebus.pdf
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d3c6bde1228---99802739765.pdf
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/495b09bb47e0913ff95bc5ec73e5fdc4/majotulipobux.pdf
    • https://jetzterstrecht.hamburg/wp-content/plugins/super-forms/uploads/php/files/k2cvq03m28u16ki7g6sps6ids2/selefalogasuneva.pdf
    • http://mega.kz/media/upload/files/suponaboko.pdf
    • https://bushregenerators.biz/userfiles/files/79125178673.pdf
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/160764e2b52937---24460868536.pdf
    • https://aydin-elektrik.com/resimler/files/40688837092.pdf
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a9380542f67---lojaropazexevizudiv.pdf
    • http://www.vikingmaterials.com/img/6134795927.pdf
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/09d7d37b13d475d5de827d717a76a76d/fisofenorizemiwavuxekib.pdf
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/160af97fa98d92---wunosekowibivogut.pdf
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b57f8d1e6b---33884917739.pdf
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/edf777f4929ff7bb649bd1c7f475a5a7/31735711727.pdf
    • http://brucemsmithlaw.com/clients/e/e2/e252bfde01ef004f685a9648d307a4b9/File/pawubugatol.pdf
    • https://staffxrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/6ecec63137f505f021f3300b9c0af184/57136409475.pdf
    • http://nadiadsa.org/userfiles/file/87173560309.pdf
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/c90fd9e58ccfddc8951a4da421d560bf/liburuwadegebufosit.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_off0000eff0.bin
605d844ec9ce372ef8fde7f97e7d717a01b6747ba83d1e5a8b278a79323f89b0
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFF0 9568 bytes
font_01_sfnt_off000104a1.bin
db7ca15d7e1ddf999100c8239f395a4d6b2c6876be696fa82e472f456eb29e97
pdf-font-stream PDF embedded font (sfnt) at offset 0x104A1 18936 bytes
font_02_sfnt_off00013494.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13494 16792 bytes