Malicious PDF — malware analysis report

Static analysis result for SHA-256 19cef403e5cd0768…

MALICIOUS

PDF

101.1 KB Created: 2021-09-06 13:08:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 96cf89a6e51ffcefd28ee3bd09477512 SHA-1: 68959795731dd2f48666cfeb2497550bfb7d0f5b SHA-256: 19cef403e5cd0768af6e2762cf98320e66df414e3e03e1e4ff25be206a71be78
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a phishing or malicious redirection scheme. The ML classifier and ClamAV detection strongly indicate malicious intent. The file's structure as a link farm is designed to lure users to external, potentially harmful, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9938

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://krisoc.ru/uplcv?utm_term=rewilding+european+landscapes+pdf
    • http://mauchlineware.com/html/chapelstreet/web/userfiles/files/vifejuwidezafabepo.pdf
    • https://isabellepieman.com/userfiles/file/biwala.pdf
    • https://cor.org.ar/wp-content/plugins/super-forms/uploads/php/files/tfh8uqam9ah1bh540u0naj2a30/pesoparasup.pdf
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160b4663eadcc0---88967312924.pdf
    • http://stihoplet.by/upload/editor/files/didipiro.pdf
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160931e0bd2e04---wedilolinebuv.pdf
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/e5a8417c988a7f5d0820507d82fe9591/jumelejelo.pdf
    • http://suachuaspa.com/upload/images-content/files/xeloropokaneb.pdf
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085eb5059b6b---57636786719.pdf
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/pejin40dlieqlrbde2s4b9ul83/24062549659.pdf
    • http://1960vonsteuben.com/clients/d/df/dfb5e1b83ea85bfdc5ef1da934264264/File/71798874879.pdf
    • https://www.ergunaygoren.com/wp-content/plugins/formcraft/file-upload/server/content/files/160802faad8c16---bovemena.pdf
    • http://ordinate-ltd.com/file_media/file_image/file/42438172921.pdf
    • https://luxmarketing.agency/wp-content/plugins/super-forms/uploads/php/files/4dkq9m8tp41v45vtbhvvmb7jpk/rubusinabo.pdf
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16073374cb2a0b---zupibalusidimiraralat.pdf
    • https://edarky.net/data/file/budevazusiwazokipebaso.pdf
    • https://sunwayhk.com/louis/STARKGROUP/ckfinder/userfiles/files/lipagomumovutew.pdf
    • https://johanbjerke.se/userfiles/file/piwelo.pdf
    • https://ww150001.linebot.net/upfile/files/20210826154420.pdf
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cb302b58cf1---15417336700.pdf
    • https://civilkontroll.hu/uploads/file/92723394151.pdf
    • https://ukdirectremovals.com/wp-content/plugins/super-forms/uploads/php/files/fa0f37866da67759d951a6eece006cfc/kikirejonofegewumul.pdf
    • https://www.pennlighting.com/wp-content/plugins/super-forms/uploads/php/files/837b5f4cf09896205fbdc6b2f6299ed4/sovavawepoxudu.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_off000120f9.bin
edb3607a6b7bd41a185720eee3bc391120b8658f6b762d7cd833927f85464cb7
pdf-font-stream PDF embedded font (sfnt) at offset 0x120F9 19940 bytes
font_01_sfnt_off000155d7.bin
5bdce622bf8938fd439312aed0bdede4b2c4037328486a0850231ed101526641
pdf-font-stream PDF embedded font (sfnt) at offset 0x155D7 10928 bytes
font_02_sfnt_off00016f1f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x16F1F 16792 bytes