Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb37cfc9143cc3e8…

MALICIOUS

PDF

74.9 KB Created: 2021-06-26 07:52:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: b2c63e6482f47685bda9701354ea29d1 SHA-1: b03a663b9ad734c37aefa276271501f81d1c595b SHA-256: cb37cfc9143cc3e8b37c7eddd48b474df60da5c735e6dbe919d32268f5c994c2
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many hosted on compromised WordPress sites or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. Although no scripts were explicitly extracted, the nature of the URLs and the heuristic firings point towards exploitation of PDF vulnerabilities or social engineering to lead users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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 https://queure.ru/uplcv?utm_term=judge+this+cover+brittany+renner PDF link annotation
    • https://trouver-une-ssii.com/img/pics/files/suwibazobowarivekop.pdfIn PDF document text
    • https://mobiligennari.com/userfiles/file/23491551478.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16088558457bbd---22148871600.pdfIn PDF document text
    • http://gertiesbloomers.com/kousumi/nulook/upload/fckimages/file/85823277190.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16092cdf7de16d---posilefuzuwidawe.pdfIn PDF document text
    • http://vuatoyen.com/uploads/userfiles/file/21019205831.pdfIn PDF document text
    • http://dientrotiendathc.com/media/ftp/file/wiworifufu.pdfIn PDF document text
    • http://gernano.eu/gfx/userfiles/files/42097938501.pdfIn PDF document text
    • http://ural-kip.ru/admin/ckfinder/userfiles/files/60703427501.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afb5cd4ed17---dedafelovofesopiput.pdfIn PDF document text
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/f43203185c9150905392eff884ca2397/nejusubo.pdfIn PDF document text
    • https://reflexlighting.com/wp-content/plugins/super-forms/uploads/php/files/fad5794a5da9054692a6a400bb75ec49/pidokiwub.pdfIn PDF document text
    • http://tivatijapan.com/uploads/userfiles/file/15318637063.pdfIn PDF document text
    • https://ottenburger.com/userfiles/file/javemigiferajilisebejonu.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081b7b7653a6---zidolobaguzegatizava.pdfIn PDF document text
    • http://cnpair.com/userfiles/file/76076625463.pdfIn PDF document text
    • https://www.emma-solutions.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b96cbb534ef---59399894715.pdfIn PDF document text
    • https://www.beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/fcfb716b3c97adc1947950626678ab20/robevirameluziwekimisefi.pdfIn PDF document text
    • https://ajur.rest/uploads/userfiles/file/difujoxuwik.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/39441936.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608724414f8f2---welusududizoniwu.pdfIn PDF document text
    • https://www.anandtirth.com/wp-content/plugins/super-forms/uploads/php/files/67dp4cgisiioi7l49evloubpf0/42894431663.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ff9af7b9d1---pesapaperiwawoxupum.pdfIn PDF document text
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/9u6i4t56h7a7m1m8n7tqcupc9h/24348441167.pdfIn PDF document text
    • http://bartuceviri.com/userfiles/file/77447659006.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/n5fk9t6bqmedhqovkfv45rem25/nurogixokosoxurozetobit.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_off0000bf5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF5A 16816 bytes
SHA-256: f29ae948e8cce6ef5623fd8b2a656440155a54a3e6b3e892934c48fca0ae8828
font_01_sfnt_off0000eb39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB39 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010350.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10350 11012 bytes
SHA-256: 9da294cc18e6cb09f87b17d8fe9bde13ef690a3273285e7236a2cafae8632840