Malicious PDF — malware analysis report

Static analysis result for SHA-256 8535f8bba82b700a…

MALICIOUS

PDF

84.4 KB Created: 2021-09-16 21:31:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 24d0f97b6f7f8fb6e76fba38ad7b2b98 SHA-1: 954558b93052d3e6b05f1ecf502cdcb43d4e1ed4 SHA-256: 8535f8bba82b700abd761d60989925f8faa482ae6aef8d09a683687df4be00ba
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, and contains embedded JavaScript. It also exhibits characteristics of a link farm, with numerous URLs pointing to potentially compromised or disposable hosting, suggesting an attempt to redirect users to malicious sites. The presence of JavaScript indicates an intent to execute code within the PDF, likely to facilitate further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 7

  • 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.
  • 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://ketchas.ru/uplcv?utm_term=is+it+bad+to+put+a+refrigerator+on+its+side
    • http://www.its-dph.cz/admin/fckeditor/editor/userfiles/file/pusufoxekejo.pdf
    • http://dbcasagayathottam.org/assets/uploads/cms_images/files/wodomoborifasuwili.pdf
    • http://huiking.cn/uploads/file/021125062235.pdf
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/2089efe863d20967c21b585ac227712e/nedafenafolenikenokanozaj.pdf
    • http://unsersohn.ch/images/file/gexotulawolusituramugi.pdf
    • http://szintai.hu/ckfinder/userfiles/files/momikanerotasowumulemava.pdf
    • http://garantc.ru/userfiles/file/dexivedopanewizaxu.pdf
    • https://eurotig.ro/file/rexinirunanaliwixebor.pdf
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/7057fb3972931a31fe7a954e9bf02631/pupibixamivimub.pdf
    • http://dgelc.com/userfiles/file/20210905111342.pdf
    • http://phrabat.net/UserFiles/File/dapodobepemekokevokexigex.pdf
    • https://banktapeunadana.com/tapeunadana/bank2/admin/userfiles/file/19082522046.pdf
    • http://spartapr.com/images/upload/file/sasikeraligudo.pdf
    • http://gndpta.eu/news_objects/files/nexizefiradi.pdf
    • http://saltokisport.com/uploads/files/kenag.pdf
    • http://faithleader.org/js/ckfinder/userfiles/files/45421179689.pdf
    • https://newtech-utm.pl/userfiles/file/38605037440.pdf
    • https://mavachhaiphong.com/upload/files/41308135609.pdf
    • http://legalinet.eu/userfiles/files/xowevejesuv.pdf
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130d11a5f21d---gijametenuk.pdf
    • http://xn--3bsx3iw22bmot.com/filespath/files/20210906165734.pdf
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/6f8f43cd34c3e4c93ff2a2f5de88bf4b/jumurizuxinumumisadide.pdf
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e6c8dd89ef---13824745588.pdf
    • http://goddesshair.net/upload/users/files/tokif.pdf
    • http://bodemveenweiden.nl/bodem-veenweiden-img/lunafewixax.pdf
    • http://www.tahi.hu/ckfinder/userfiles/files/bozivamibimizod.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_off0000e4a5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE4A5 16792 bytes
font_01_sfnt_off0000fcb7.bin
79a44140fe499a026d65d917ea87fdebd3dcf1582c4284bf1656994062f4990a
pdf-font-stream PDF embedded font (sfnt) at offset 0xFCB7 17772 bytes
font_02_sfnt_off00012abc.bin
76939bd68f503e5836ef3e3fcff88d31b1f85dbda7c117ec86f24c1b8c10aac2
pdf-font-stream PDF embedded font (sfnt) at offset 0x12ABC 10816 bytes