Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c68139687676f15…

MALICIOUS

PDF

76.1 KB Created: 2021-09-07 12:28:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 538004b77c002d75c78862799fe46239 SHA-1: 7565536a2ecf70da41a066be578b4be70eafabcb SHA-256: 3c68139687676f15aaf829012a38b79f2c5e74e59cd26b2f8ede007f6f7e66db
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many hosted on compromised CMS uploads, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and link farm heuristics point towards an attack pattern involving redirection to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://www.supair-lux.hu/ckfinder/userfiles/files/8163496740.pdf In PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c077bb40261---51544008425.pdfIn PDF document text
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090340bf3d2b---fasew.pdfIn PDF document text
    • http://nedirajtebosnu.net/userfiles/file/71257732602.pdfIn PDF document text
    • http://orourkelawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jetud.pdfIn PDF document text
    • http://rasmesafar.net/basefile/basefiles/xepagopezuvi.pdfIn PDF document text
    • https://sygimportaciones.com/wp-content/plugins/super-forms/uploads/php/files/r6uthnm3jtrdonqtnv8vf7rjrs/35878074077.pdfIn PDF document text
    • http://rhodeislandalpha.com/clients/56223/File/nuvatitogatu.pdfIn PDF document text
    • http://shreejians.com/userfiles/file/kibimadenoko.pdfIn PDF document text
    • http://citadelcaralarms.com/userfiles/file/mutexuko.pdfIn PDF document text
    • https://stbenedikt.ch/userfiles/files/98018567507.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160c2a608cc14d---warugarawona.pdfIn PDF document text
    • http://fsgpj.com/upfolder/e/files/20210731202730.pdfIn PDF document text
    • http://studiotecnicoprato.eu/userfiles/files/71228166373.pdfIn PDF document text
    • http://dulwichtaxi.com/survey/userfiles/files/38201344152.pdfIn PDF document text
    • http://simonhoirup.dk/userfiles/file/zuwulusuwigaditeraras.pdfIn PDF document text
    • http://wawa757.com/uploads/files/memuzogexatorekowifub.pdfIn PDF document text
    • http://55pluscommunityspecialist.com/userfiles/files/sumapisesolelopofuno.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b0615931c8a---25772047333.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/160edd7ee03dc8---nuwudovefifubibe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=what+are+acids+bases+and+salts+worksheet+answersPDF 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_off0000c56c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC56C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD83 10780 bytes
SHA-256: f8e8ab610187611d20003e42a0db8971797471017566d5511cb3c54033ebffef
font_02_sfnt_off0000f650.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF650 17432 bytes
SHA-256: 864ca43a29ab8d2c76e76a8c177c4630cb5c5dcdeeed696b214834bc6a2f0b81