Malicious PDF — malware analysis report

Static analysis result for SHA-256 261757f6c2734008…

MALICIOUS

PDF

78.3 KB Created: 2021-07-05 07:49:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 79ecf93b4f536008817d16f5ee857eb4 SHA-1: 4419f74485d8f1f149729541d90153c16de198ce SHA-256: 261757f6c273400828c7b0ba96163f37bde502ed1246bc5e422b276630f267c5
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. It functions as a link farm, containing numerous URLs pointing to compromised CMS upload directories, likely intended to lure users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ad21cb4d27c---25997227412.pdf In PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bc1e2e5207c---90499634833.pdfIn PDF document text
    • http://bpsstudio.hu/uploads/2077107375.pdfIn PDF document text
    • http://fine-cottage.ru/userfiles/files/pupotipekol.pdfIn PDF document text
    • http://szao-spb.ru/images/news/file/didusolokiruve.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a77649591d3---wufifenenatofidurapitaba.pdfIn PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/f0e3ced9ae90b08f28d6a275a9379914/87491823125.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/rasokufajigufu.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/51eb0cc5c22c7d3933fd446618998bcb/funikabebir.pdfIn PDF document text
    • http://traditionsradio.com/wp-content/plugins/super-forms/uploads/php/files/gn0vqbq0d8vidd7da5st538ot5/wumebirurekirekitagatot.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160c909e023fe7---sorenamorunofuni.pdfIn PDF document text
    • http://kinel-hunter.ru/upfiles/file/61236766309.pdfIn PDF document text
    • http://thebellingerfamily.com/clients/0/05/05034faaa501c69409a7459485cba135/File/79551046747.pdfIn PDF document text
    • http://budohurtsa.pl/userfiles/file/11030395088.pdfIn PDF document text
    • https://alternativecarrepair.com/userfiles/file/56726642344.pdfIn PDF document text
    • http://rdmsrl.it/userfiles/files/xolabuvositim.pdfIn PDF document text
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/1jkpcs949u8gsa9g8uv53p7ei0/xexamurevawamixi.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160a039b414c7c---70368382983.pdfIn PDF document text
    • http://all-pass.com/folder/editor/file/gowanezasisi.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160798de92495a---mumezadubovunedobulini.pdfIn PDF document text
    • https://jambukuning.com/contents//files/96609576477.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=two+isosceles+triangles+are+always+similarPDF 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

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d006.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD006 16792 bytes
SHA-256: 44487a1b4b6606521854c407a1229e29c636c43bbda41eeda1f70bc7bf79f1a0
font_01_sfnt_off0000fbc2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBC2 10736 bytes
SHA-256: c34476b3dbdc9d708106ad630e70a5b47a8330535045bf657476ec3f9fbb6212
font_02_sfnt_off00011490.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11490 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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