Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7760a1786c113ef…

MALICIOUS

PDF

76.6 KB Created: 2021-09-03 00:51:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: fceca0032c9a30616708638372d23bf0 SHA-1: 7e5814c43afc0b707c9646c8450349c97f0b9f84 SHA-256: a7760a1786c113efbfd051329b3a38b3f3b0bad673fb7f45f2a48ac2a6200683
236 Risk Score

Malware Insights

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

The PDF document contains multiple links to external websites, many of which appear to be compromised CMS upload directories. The heuristic 'SE_BROWSER_INSTALL_LURE' indicates the document's content is designed to trick the user into installing a browser extension or update. This, combined with the ML classifier and ClamAV detection, strongly suggests a phishing or malware distribution attempt. No scripts were extracted, but the presence of numerous external links points to a downloader or redirector pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9939

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1608230ae031da---mifugix.pdf In PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/kcnerlnj8behma5jh8uebhokg1/45369851558.pdfIn PDF document text
    • http://tea-ra.com/user_data/upload/save_image/files/xomunoladurukegivol.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/27c962fca03f3aa186cbd6a19da272e3/44536530863.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5948163220---weboxazolakeragevesesemas.pdfIn PDF document text
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/gqgmu83mkradvjhed4dm65ol82/84625159655.pdfIn PDF document text
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1607f1a7634279---97839652168.pdfIn PDF document text
    • http://hitecds.com/userfiles/file/mulew.pdfIn PDF document text
    • https://cutandcolorparrucchieri.it/file/42211730098.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/6b7fc2a1608d6025a54ad1de7fd2de1d/dotanibusudifi.pdfIn PDF document text
    • http://wang023spa.com/userfiles/202106file/2021062303125970554.pdfIn PDF document text
    • http://american-security-inc.com/assets/ckfinder/userfiles/files/mozofisuruvigafifulu.pdfIn PDF document text
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a5ce5fd0ea5---pikopusipugemoxatajotinok.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160803a8c60df2---72609134020.pdfIn PDF document text
    • https://mvmdigital.gr/files/files/43118211397.pdfIn PDF document text
    • https://asthasupermarket.com/userfiles/file/didokevapiwowoveza.pdfIn PDF document text
    • http://assushop.com/userfiles/assushop.com/file/49519706267.pdfIn PDF document text
    • http://tksvolga.ru/userfiles/file/87838364409.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/7pm8qsg82rd5mufb3lt0jkqk33/manawopenulefajiwes.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab89069356a---2881358671.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/9ab82e5b327c56ca43cacc91d1cec59a/58166667450.pdfIn PDF document text
    • https://beautyyaurient.com/editor_upload/file/8594780726.pdfIn PDF document text
    • https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/sabc0m64bbkm4g4kfvgpfn12r5/sokomi.pdfIn PDF document text
    • https://nailseasupportgroup.com/wp-content/plugins/super-forms/uploads/php/files/49b765028dbd637c739e8525d86f4dd8/denamogufugi.pdfIn PDF document text
    • http://vet-arrighicolangelicristilli.eu/userfiles/files/30218532046.pdfIn PDF document text
    • http://banquat.com/userfiles/files/kuripiwopuxupetipexudab.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=convert+multiple+image+to+pdf+online+freePDF link annotation
    • 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_off0000c728.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC728 17036 bytes
SHA-256: e50821708af60b08d88accc3a72b68918155f3eda07bf42606cc80b3f0d8fe91
font_01_sfnt_off0000f300.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF300 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010b17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B17 10872 bytes
SHA-256: f76a760f6ff0406b9b0f933b36c407bc615e5adca7821e368750dc1d00d109c9