Malicious PDF — malware analysis report

Static analysis result for SHA-256 6444b52c15af2bd7…

MALICIOUS

PDF

76.1 KB Created: 2021-06-28 14:04:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 0ff1feaa24c361826aeedd868a09d404 SHA-1: bf6a165d162ddb15fa528b6c3736f6188795a64d SHA-256: 6444b52c15af2bd78a9ebb172b32fd356a35106f9d67b79809679152523711b9
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous links pointing to compromised WordPress upload storage and other disposable hosting, suggesting it functions as a link farm to distribute malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://wastran.ru/uplcv?utm_term=green+skills+class+9+questions+and+answers PDF link annotation
    • https://nhanloc.net/userfiles/file/mabovipamujirogagene.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086847c2bdd4---60165376073.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/6a5949bb599cb1aaa9aa7ab591504ae0/65989778424.pdfIn PDF document text
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/160d6aaa29be83---64942215533.pdfIn PDF document text
    • http://agcslohian.com/userfiles/file/78450924363.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160c19a9165c8f---bufexadutuduzoxak.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/q0pags5937668fph02ubs0l7h7/digaxuwitawuwotemof.pdfIn PDF document text
    • http://happyland-nsk.net/ckfinder/userfiles/files/94835636791.pdfIn PDF document text
    • https://www.infrascale.com/wp-content/plugins/super-forms/uploads/php/files/7ffc25c301b7808252c98b9b94c32351/tuwakirisor.pdfIn PDF document text
    • http://botanicgardenscafe.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16084313874839---24544492101.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609d327948eac---35948558495.pdfIn PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/rfa6dtdnj5g562cd1piiqlaf4k/85541786569.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a895a05b783---tuwubaga.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6c67b65662---77667444484.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16070e04137473---44164319185.pdfIn PDF document text
    • http://cablexconsulting.com/Upload/file/vekewepa.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/ced9c7170fe2609c381964f926480de9/gesoborezat.pdfIn PDF document text
    • http://imi.vc/upload/files/zagupiwajowobaxozukaku.pdfIn PDF document text
    • https://alamansyria.com/userfiles/file/90621836303.pdfIn PDF document text
    • http://alexhoffordphotography.com/temp/files/file/77597123200.pdfIn PDF document text
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070e43884b61---60492901567.pdfIn PDF document text
    • https://marbellamohali.com/wp-content/plugins/super-forms/uploads/php/files/23cf942ae392a4752cf424daeb77a096/pesanula.pdfIn PDF document text
    • https://aldurra.ly/images-editeur/img/file/befapemigufani.pdfIn PDF document text
    • https://arket.io/wp-content/plugins/super-forms/uploads/php/files/6er1dcbohj56uc96kfei2h4jcv/82146588233.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_off0000c495.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC495 16708 bytes
SHA-256: ca3cdf7c365cd2001e5a80a6c8b17992baff726d600f140bd421dffe2a887f87
font_01_sfnt_off0000efa2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFA2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000107b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107B9 10992 bytes
SHA-256: 2a8c08467df0a18294a35457bf68ac90012536ad69cb50deefcfc68bdf1bb3eb