Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c4fb8ba278c1877…

MALICIOUS

PDF

83.1 KB Created: 2021-09-06 09:52:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: a86a9969cd88986821e03761197e0a3a SHA-1: 3bfd8af53ff80f8efebdeccf30b012afb607013d SHA-256: 3c4fb8ba278c1877721292c43d04f761c12a94101b5d885798622a020e5057fc
156 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to various domains, some of which appear to be compromised CMS uploads. The primary purpose seems to be directing users to external sites, potentially for phishing or SEO spam. No scripts were extracted, but the PDF structure and embedded URLs strongly suggest a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://inwebjor.ru/uplcv?utm_term=free+greek+latin+root+words+worksheets PDF link annotation
    • http://tinavaron.com/ckfinder/userfiles/files/82139500734.pdfIn PDF document text
    • http://foodchemsino.com/d/files/pigopotatobuzeboko.pdfIn PDF document text
    • https://daluxerealty.com/wp-content/plugins/super-forms/uploads/php/files/bgp2g9rhi66idge82opgpt2270/73283361253.pdfIn PDF document text
    • https://autotrilogy.com/wp-content/plugins/super-forms/uploads/php/files/ebdde2f4deead5cae3ea23e81c00dcf1/87720098208.pdfIn PDF document text
    • http://zovsh.com/Uploadfiles/files/lonugomanipefuwidak.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608dd827be830---50545865270.pdfIn PDF document text
    • http://ahlhy.com/uploads/file/041745422672.pdfIn PDF document text
    • http://stacjaregeneracja.pl/userfiles/file/safaribugetozifapok.pdfIn PDF document text
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092b42fc65d0---kipukilotozopetowiloriv.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082bf5707a25---15705920582.pdfIn PDF document text
    • https://equator-maritime.com/userfiles/file/30730714102.pdfIn PDF document text
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d4e6917fc87---matujegopube.pdfIn PDF document text
    • https://purmoradiatoriai.lt/images/files/lerimivafulalufimometaso.pdfIn PDF document text
    • http://sbhs1967.com/clients/8/89/8985ce50e7417da620f75e2af787291b/File/netizonogisuvuduwipo.pdfIn PDF document text
    • https://tripleccompanies.com/wp-content/plugins/super-forms/uploads/php/files/7870f1b9d6ace11dd8f605938784760b/vejowoxafefem.pdfIn PDF document text
    • https://svetpoznaniyaonline.ru/wp-content/plugins/super-forms/uploads/php/files/a9fc3b7f22bdf0016f259ffc9737fcbf/30011867337.pdfIn PDF document text
    • http://nextgenship.net/upload/file/20210714162623559221.pdfIn PDF document text
    • http://phuocthuan.vn/images/pic/file/65060974074.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/66720289367.pdfIn PDF document text
    • http://vipnjl.com/userfiles/files/29351893973.pdfIn PDF document text
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/vh7ts56ba2la9hbsq7v121dggc/27255364779.pdfIn PDF document text
    • http://generaltubi.com/container/ckfiles/files/pogamewidipojejululu.pdfIn PDF document text
    • http://caminodesantiagoenmoto.com/assets/ckfinder/core/connector/php/uploads/files/wonulu.pdfIn PDF document text
    • https://www.thc.gda.pl/ckfinder/userfiles/files/67291651676.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_off0000dcf9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCF9 18252 bytes
SHA-256: 5933dc437c7e157d8262a9b4489bccc8516576fbda5b7a1dae5a321c11389352
font_01_sfnt_off00010cf6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CF6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001250d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1250D 10680 bytes
SHA-256: 05d47cc61ccfa732e1af3e3ad0bee223e447cef3bea2306c52b48e5919ef97cc