Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6bb33450751a941…

MALICIOUS

PDF

85.4 KB Created: 2021-08-05 06:59:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 0cc7382a1c49e5f6e72bd0f3f414aef8 SHA-1: 368c4997d74ece98ed15affd473c80123614316e SHA-256: a6bb33450751a941c3432de6b951a8e96a04416d3aeaf7918cb54768d199c579
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links, many pointing to compromised CMS upload storage and disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. No scripts were extracted, but the structure and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • 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.
  • 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://trhs64.com/clients/c/cf/cfad56e582d93fa9eda51f2516e23bdb/File/fudimujumevuxidunin.pdf In PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d5b7c8d261b---tabofedulo.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/137cc4f0e40119cfd025aeda5cb68102/totozazopexade.pdfIn PDF document text
    • https://georgiamusicpartners.org/wp-content/plugins/super-forms/uploads/php/files/dee2ab2fda4f999ccde3c701de85ee9a/lujuve.pdfIn PDF document text
    • https://mobiligennari.com/userfiles/file/38440249810.pdfIn PDF document text
    • http://www.klpreschool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fccab2ab67---97676522177.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/5b6d03334e55c829a043657949f72a73/jifalaxawakigi.pdfIn PDF document text
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/kjaj5tvvij18964q5cbjbe8uv4/fibadufixejuvumopunap.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/a905d8a3a99a87f1b33b227064c10494/lokusomuletogi.pdfIn PDF document text
    • http://wildzipper.com/clients/wildzipper/userfiles/file/46605076908.pdfIn PDF document text
    • http://carroll1975.com/clients/4/4e/4e2b018d07aaa5a30c3e4fca1c7a8df7/File/lofep.pdfIn PDF document text
    • http://rbtyutj01.com/userfiles/files/borujinusupe.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a08bf78118c---nutaboveke.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ec66223c3e---nugokupojifakajunufukap.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/0c3ecc19b599be151cb2f55389c2f315/2230399175.pdfIn PDF document text
    • http://peusch.lu/userfiles/files/sirigagujol.pdfIn PDF document text
    • http://netisiletisim.com/guvennet/resimlerfiles/10146050947.pdfIn PDF document text
    • http://kcemsp.org/upload/editor/file/zawagukidigagowupowo.pdfIn PDF document text
    • http://elitakhealing.com/ckfinder/userfiles/files/65800862810.pdfIn PDF document text
    • http://ladakhtripmaker.com/userfiles/files/liresu.pdfIn PDF document text
    • https://home-consult.lu/userfiles/files/36249399071.pdfIn PDF document text
    • http://worksafeorg.com/wp-content/plugins/super-forms/uploads/php/files/qpoq73dkuqbhvoc9u6tutas583/burosawum.pdfIn PDF document text
    • https://albawadiroad.com/userfiles/files/7885680331.pdfIn PDF document text
    • http://jr-bang.com/uploadfiles/20210621022030.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=topics+for+economics+project+class+12PDF 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_off0000ea3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA3F 17024 bytes
SHA-256: 0f01437bc625955b6cde465d950e34a47e227f83ba686745d79f1e4c8e7f6482
font_01_sfnt_off00011683.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11683 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012e9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E9A 10904 bytes
SHA-256: 35a6d338ff459c188ecbbdb0a2d2557250f84b14ea026719f4b9cbfce5345a33