Malicious PDF — malware analysis report

Static analysis result for SHA-256 7cdbddb9cbe772e3…

MALICIOUS

PDF

77.9 KB Created: 2021-08-18 22:47:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-16
MD5: cd0da46127ca1c38ae62f442f7b51c7b SHA-1: 89bb228228bddac5789378bd957d9d1503264e6f SHA-256: 7cdbddb9cbe772e34a3e0b630a62ba8915ebd6e0d9e067ce4a83d98980230a3c
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF contains embedded JavaScript and a large number of external URIs, many of which point to compromised CMS uploads or are part of a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing or malware distribution sites. The embedded JavaScript is likely used to facilitate these redirects or exploit PDF vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9939

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://irlanc.ru/uplcv?utm_term=spanish+subjunctive+practice+with+answers PDF link annotation
    • http://cukierniabrzezinski.pl/www/artizam/fck/file/jogub.pdfIn PDF document text
    • http://e-hematologica.com/users//file/lipupolijolibajoko.pdfIn PDF document text
    • http://geredekombiservisi.com/userfiles/file/11473795345.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/aec77fec36e9804b366fb9f121d866ba/56065649569.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/gv214uq2l0e8h8i0iddfr0k895/xanuxupovudupov.pdfIn PDF document text
    • http://bean2beenefamilytree.com/clients/60578/File/zuvifapofatiwutaveveru.pdfIn PDF document text
    • https://sitebyside.ru/wp-content/plugins/super-forms/uploads/php/files/69bbcc9cf594e1848c36226dddf4a41b/piteb.pdfIn PDF document text
    • https://035620126.tw/upload/greenkitchen/files/nopufudalupisupofagaxax.pdfIn PDF document text
    • http://unipsyclinic.com/userfiles/file/20210518074612.pdfIn PDF document text
    • https://www.nordatec.com/wp-content/plugins/super-forms/uploads/php/files/dtpmpd7bd1morb7atetf54t7ca/ripubovote.pdfIn PDF document text
    • http://fujiya-la.com/uploads/files/vizejenijedu.pdfIn PDF document text
    • http://ssaisarang.com/ckfinder/userfiles/files/nobafonevovudezazolurir.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160778920c074d---mawonimudirubekomolivuf.pdfIn PDF document text
    • https://picinterior.com/ckfinder/userfiles/files/42030181557.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160996b5f7fbf2---nisiginodasemexosakol.pdfIn PDF document text
    • http://www.phsdcenter.com/temp/js/ckfinder/userfiles/files/legaxagitabalezexifavuwed.pdfIn PDF document text
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/46df2badd8624ed9de5264246598306c/kilizetepepezopijotamaf.pdfIn PDF document text
    • https://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/59tvgaj52e7tk6fr1aoiqvj0e6/kasure.pdfIn PDF document text
    • https://www.lashharmony.co.uk/wp-content/plugins/super-forms/uploads/php/files/hp9umjp19s4oode2tm2886sj1t/24338389292.pdfIn PDF document text
    • http://anm-av.de/uploads/files/37966122792.pdfIn PDF document text
    • http://aprendanow.com/wp-content/plugins/super-forms/uploads/php/files/db649ec28f0e36f55ab08fc99eb0d046/depijoziwejedujak.pdfIn PDF document text
    • https://mma-montessori.com/admin/ckfinder/userfiles/files/12760854506.pdfIn PDF document text
    • http://bilmatbasim.com/userfiles/file/94973920953.pdfIn PDF document text
    • http://tcsm62.org/uploads/news/file/9816138959.pdfIn PDF document text
    • http://leaguengn.com/userfiles/file///xedogulimolisozogaberaj.pdfIn PDF document text
    • https://hondamienbac.vn/userfiles/file/tibodolum.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_off0000c8c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8C1 10904 bytes
SHA-256: b7f03dbad88a7ad2d0af6d023327f0d8d763083bcb568a466ef3fddae82f767a
font_01_sfnt_off0000e1c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1C3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f9d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9D5 18376 bytes
SHA-256: cf860af801dab818da41502843a9424563eaf41e821bd18919713d65eb9c2d33