Malicious PDF — malware analysis report

Static analysis result for SHA-256 515b65ead201d077…

MALICIOUS

PDF

83.0 KB Created: 2021-09-11 09:07:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 471753b48cea41afd730f62c4ea062aa SHA-1: 034f3ad83b75b126703de829a24d6431a182ecf5 SHA-256: 515b65ead201d077a3bc753d4838f87f82d6ebd2e3eee43f642ecb1cfddca9af
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, and it contains embedded JavaScript. Several heuristics indicate the PDF is part of a link farm, with many URLs pointing to potentially compromised or disposable hosting, suggesting an attempt to redirect users to malicious content. The presence of JavaScript and numerous external links strongly suggests the PDF is designed to exploit vulnerabilities or lead users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://hotelniagararimini.eu/userfiles/files/nogevofexataze.pdf In PDF document text
    • https://gulamanis.com/contents/files/xejuvidorutudawexo.pdfIn PDF document text
    • https://www.traitagri-solutions-alternatives.fr/ckfinder/userfiles/files/piganasukowoxovutidu.pdfIn PDF document text
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/wudedigulolibufavobasuvak.pdfIn PDF document text
    • https://royal-art.pl/uploads/userfiles/files/giruwodarame.pdfIn PDF document text
    • https://gazeta-msp.pl/user_files/File/domapevebuxozunox.pdfIn PDF document text
    • https://cornerstonelaw.eu/userfiles/file/15995450327.pdfIn PDF document text
    • http://kanizsakran.hu/userfiles/file/xamagobupowobudo.pdfIn PDF document text
    • http://cctsw.net/whly/up_files/FCK/file/20210908_015550_154.pdfIn PDF document text
    • http://work4shop.cz/userfiles/file/82527593548.pdfIn PDF document text
    • http://co-mit.com/uploads/files/61035848806.pdfIn PDF document text
    • https://abrasco.org.br/ckfinder/userfiles/files/zavaxoboru.pdfIn PDF document text
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/orr2u57h1jldv6elps8ospm5u7/fezavejunarujape.pdfIn PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///567409104.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/tijikes.pdfIn PDF document text
    • http://somsit.com/ckfinder/userfiles/files/76125251856.pdfIn PDF document text
    • http://webursitet.org/Files/file/63678692683.pdfIn PDF document text
    • https://warungmimpishio2.com/contents/files/tibigigurekolulojor.pdfIn PDF document text
    • https://al-farh-iq.com/upload/userfiles/file/42977743847.pdfIn PDF document text
    • http://kingsbrite.com/kingsbrite.com/userfiles/file/68229233097.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613372d7bb45a---mitutuborutikasopagemu.pdfIn PDF document text
    • http://hocomesun.com/upload/25413734882.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/1613755e1e3614---fupixejumotunikuzafevimib.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=calculating+simple+interest+worksheetPDF link annotation
    • http://www.cst.rnu.tn/js/ckfinder/userfiles/files/sazamasevozesogelole.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_off0000dd1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD1F 11132 bytes
SHA-256: ae510a747d500b912f81ad7f3b2de3d49b66da19ee619af5dbd67d5b5b7f1431
font_01_sfnt_off0000f6f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6F9 18412 bytes
SHA-256: fe524bb4ff568e72f14142c4cf3c726b4131f273e519ffa1a4af491a58168b01
font_02_sfnt_off000126b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126B0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1