Malicious PDF — malware analysis report

Static analysis result for SHA-256 13f081a4ffb161ef…

MALICIOUS

PDF

92.8 KB Created: 2021-08-12 17:46:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: dcbd6aecc035e6b9be0b2704ac5e4831 SHA-1: 21a5fc71924488a0b25526ff81e22e7a5175aadb SHA-256: 13f081a4ffb161ef3a12141889adb61b94f83a558219781c29bb644ad2fbbdee
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many of which point to WordPress upload directories on various domains, suggesting a link farm hosted on compromised sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the structure and URL patterns are consistent with malicious PDF lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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 http://entone.es/wp-content/plugins/super-forms/uploads/php/files/966fbec5d0e3a7e0336b7ad4b8a22f01/6630737930.pdf In PDF document text
    • http://bethtikvahevents.ca/clients/2/20/20a91c0cb94b02964b0d1c5d980f1596/File/3154076616.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a0d6f730b9---38199390093.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/o2380hqpeqbci8h8j8ln4e2mvu/ranekulusa.pdfIn PDF document text
    • http://unternehmensberatung-hegenbarth.de/userfiles/file/85579450973.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/zeduxuve.pdfIn PDF document text
    • http://cokhihoangvinh.com/uploads/userfiles/file/52512482476.pdfIn PDF document text
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1607dbcd5ddea2---dudogetetujoji.pdfIn PDF document text
    • http://vizcsap.hu/files/file/radetojisuto.pdfIn PDF document text
    • https://marigabung.com/contents//files/68366410401.pdfIn PDF document text
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/du1q0gpms8fdi8t84rh8igc3dr/749533566.pdfIn PDF document text
    • https://www.idromeccanicasrl.com/idromeccanicasrl.com/wp-content/plugins/super-forms/uploads/php/files/25ef4c7d55ea07d48760b6af51bbb870/95191005600.pdfIn PDF document text
    • http://kemnhapkhau.com/upload/files/legumiwepajupawapobukezof.pdfIn PDF document text
    • https://cashmeredreams.com/wp-content/plugins/super-forms/uploads/php/files/b7573ca1b448db672d9e680156b7809c/7314869415.pdfIn PDF document text
    • https://kolbandibileklik.com/resimler/files/7660698433.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607cf410eb1d5---30899913636.pdfIn PDF document text
    • http://sieuthikhoacaocap.vn/upload/files/60548896418.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160766e25bd7a4---kejimivasirawubaka.pdfIn PDF document text
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/a940e5cda610acf0cc0ae5d3dff90588/39745208365.pdfIn PDF document text
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/bd21308c6b634a2220036f2397394f50/23097420723.pdfIn PDF document text
    • https://ppkh.net/userfiles/file/21292456806.pdfIn PDF document text
    • https://travelworld.ro/userfiles/file/72555305100.pdfIn PDF document text
    • https://www.kasekimi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f608e5a3d9---pigepavedekizuse.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/160ca629e571fa---79203435806.pdfIn PDF document text
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/10e9134bb39de44deea2e013a045ebf5/56270300494.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=what+color+sheets+go+with+grey+bed+framePDF 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_off00010545.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10545 11152 bytes
SHA-256: cb94b0ab5ab2293d16e7e4a1e448f1e67344be38c60f08034d7fae96d166b6eb
font_01_sfnt_off00011f36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F36 17192 bytes
SHA-256: 1d4151d84faa0105f76d863d2cbfef802e6cc7a21e524d3a8bac716466d0f675
font_02_sfnt_off00014c00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14C00 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1