Malicious PDF — malware analysis report

Static analysis result for SHA-256 5df35dce9c4bd3fe…

MALICIOUS

PDF

76.5 KB Created: 2021-09-17 01:58:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 41360e7162b924aea8d19688ef226a49 SHA-1: c59890390de6900de673dabccfc18fd8f43ef2b8 SHA-256: 5df35dce9c4bd3fec31534ab1d47cac4b70415983c8537220b66eb6f0020965d
156 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed for malicious redirection. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable, but the URL structure and heuristic firings are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://ngonluathan.com/images/ckeditor/files/vofilod.pdf In PDF document text
    • https://hefcom-hydraulics.com/ckfinder/userfiles/files/64760648471.pdfIn PDF document text
    • https://mygamedaysports.com/wp-content/plugins/super-forms/uploads/php/files/8efa0388d79fe5b168aecb897d27cda9/ruzabobarelaxe.pdfIn PDF document text
    • http://mskgroup-spb.ru/upload/file/8456348941.pdfIn PDF document text
    • https://nuttydog.hu/ckfinder/userfiles/files/votaka.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/161405af9b43d8---40718841860.pdfIn PDF document text
    • https://lufty.cz/UserFiles/files/52342093760.pdfIn PDF document text
    • http://klick-tipp.info/ckfinder/userfiles/publics/files/77351589396.pdfIn PDF document text
    • http://goldenmallbiotech.com/upload/files/89060153798.pdfIn PDF document text
    • https://ppntassone.it/dati/upload/file/94487620518.pdfIn PDF document text
    • http://alvitraders.com/files/vuxivatoselawiwamofidi.pdfIn PDF document text
    • http://web5gstore.com/Files/files/27309797361.pdfIn PDF document text
    • http://teranor.com/ckfinder/userfiles/files/xegebodusulod.pdfIn PDF document text
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/161419e5d2c8e6---64177671631.pdfIn PDF document text
    • http://www.goldenlantern.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613e62155658b---4389682855.pdfIn PDF document text
    • https://nsck-cykelmotion.dk/userfiles/file/65488075199.pdfIn PDF document text
    • http://www.chp.pl/ckfinder/userfiles/files/mozuwidurovux.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613d557676b5f---mugut.pdfIn PDF document text
    • http://designklasse.de/ckfinder/userfiles/files/37909227946.pdfIn PDF document text
    • https://webshopplus.nl/app/webroot/files/userfiles/files/71038834682.pdfIn PDF document text
    • https://eltechma.com/zdjecia/fck/file/filetewawubarunaxi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=god+of+war+4+thorPDF 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_off0000c454.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC454 10112 bytes
SHA-256: 8b569d7ffa8a7a99bd2105013928fba34f245a5709668b98e2064ede453d0c3f
font_01_sfnt_off0000db28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB28 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f33a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF33A 18844 bytes
SHA-256: f56b2312839c102e82ca7667c467c6ec21925698f201d864c7f1678ba05690ed