Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b8515803671cdd1…

MALICIOUS

PDF

88.4 KB Created: 2021-06-29 00:17:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 942478df075b0678120bf1cb79853305 SHA-1: 488de18403caacdaa8f20891ff6431f96e06f219 SHA-256: 4b8515803671cdd1c338c6420809db4dba77fc606e77f4e095281c1e4e5d5b90
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URLs, many pointing to compromised CMS upload directories. The heuristic firings indicate this PDF is part of a link farm designed to direct users to potentially malicious content, with a high ML classifier score and ClamAV detection confirming its malicious nature. The embedded JavaScript likely facilitates the redirection or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://coretry.ru/uplcv?utm_term=daily+geography+practice+grade+5+answer+key PDF link annotation
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/35826580190e9cd206f38e041fc8bfae/ralilejizagobegunaxo.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afea90c34f6---serogow.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077a24d61589---fesaledudaworag.pdfIn PDF document text
    • https://www.demetagras.com/wp-content/plugins/formcraft/file-upload/server/content/files/160726083af1d5---35593162374.pdfIn PDF document text
    • http://udaybharat.in/ckfinder/userfiles/files/fovafana.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16097a267d9b69---nisawikuto.pdfIn PDF document text
    • http://clair-environnement.eu/catalogue_dynamique/file/razadomalibeleko.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a410b80365c---23622119472.pdfIn PDF document text
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/ca8e01d2dba79d0ad85169195d1d837d/muvopa.pdfIn PDF document text
    • https://jclifeschools.org/wp-content/plugins/super-forms/uploads/php/files/88c3180011e5449b9264e1e1b573f8e1/9472648235.pdfIn PDF document text
    • http://theettiares.com/clients/f/f0/f03dfc1790708d0b03c48e9879ef2ea6/File/78529116441.pdfIn PDF document text
    • http://alwaditrading.com/userfiles/files/68017440531.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16072547b9e907---niposipakaxawuzag.pdfIn PDF document text
    • http://winecellarkeeper.com/ckfinder/userfiles/files/vafefawixenosi.pdfIn PDF document text
    • http://burningspearmarketplace.com/js/ckfinder/userfiles/files/43065601535.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a0949ad8c92---gilokepefozevarilonot.pdfIn PDF document text
    • http://kimbuunguyen.com/uploads/userfiles/file/xezakonipiruxodenuduf.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160d9af9b1f4bc---lumupaf.pdfIn PDF document text
    • https://travelsafeway.com/userfiles/file/40126010037.pdfIn PDF document text
    • http://fzsvybbs.at/userfiles/file/74744957454.pdfIn PDF document text
    • http://alexlunacoach.com/img/editor/file/2296317730.pdfIn PDF document text
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1609a176b56575---8995268441.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/180be6863e2ad4e69ce385841138cbd5/mamuxonabirajosibit.pdfIn PDF document text
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/5c9ac49b265ef6e3b60377bc3b28ad1a/87111565325.pdfIn PDF document text
    • http://apluskleaning.com/admin/images/file/puzisagukagepijisonuxun.pdfIn PDF document text
    • https://widepolymers.com/userfiles/file/zilemofimekefoganemukate.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_off0000f4d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4D9 17472 bytes
SHA-256: 3590366b7469506f99a3be6310a6cd530f1c7ce6c17600920fe516678d692cbb
font_01_sfnt_off000121d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121D3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000139ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139EA 11220 bytes
SHA-256: c28bb87c3a708b0ef0e1d5d8b9fc7124d821fcac8d3cf35e8c14e03f89c23c24