Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1b1457d98dfe2b2…

MALICIOUS

PDF

73.2 KB Created: 2021-09-22 17:59:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 6158f560677c39fb0e99d6f03f12251b SHA-1: 1e6a1875b84153a0d151006a974ff79e5346b0cf SHA-256: f1b1457d98dfe2b22663722d1cd8d16e26afcf2adae369de7355904f3bebbee1
126 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristic analysis revealed it functions as a link farm, embedding numerous URLs that likely lead to phishing or scam content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.allterra.group/wp-content/plugins/super-forms/uploads/php/files/e7e0cea3dcd53ac12431cd38fa7c8988/93727485517.pdf In PDF document text
    • http://sherwoodchambergolf.com/ckfinder/userfiles/files/66013148390.pdfIn PDF document text
    • http://buyyoutubecomments.com/ci/userfiles/files/nipuk.pdfIn PDF document text
    • http://umbabox.com/userfiles/file/85288184581.pdfIn PDF document text
    • http://dallard.fr/ressource/site-image/files/vazutidovefade.pdfIn PDF document text
    • http://podolsk-kondicionery.ru/upload_picture/file/fusel.pdfIn PDF document text
    • https://condicionamentofisico.com/arquivos/file/pisafabetedukitil.pdfIn PDF document text
    • http://oralrem.kz/ckfinder/userfiles/files/dovatujumapaxenogegeg.pdfIn PDF document text
    • http://miskolciharsona.hu/pictures/file/dabufipamito.pdfIn PDF document text
    • http://media-production.net/admin/ckfinder/userfiles/files/bofefikufaj.pdfIn PDF document text
    • http://sintjorisparochie.nl/userfiles/file/57868066613.pdfIn PDF document text
    • http://tv-sat.cz/userfiles/file/38608626342.pdfIn PDF document text
    • https://insinkerator.us/images/uploaded/file/runuxafokowazoxotudo.pdfIn PDF document text
    • https://khonggiansangtao.com/platformecom/img/upload/file/45612593323.pdfIn PDF document text
    • http://www.motionmantra.com/userfiles/files/33338646196.pdfIn PDF document text
    • https://ferropula.hr/files/40542117497.pdfIn PDF document text
    • http://brenno-tojestto.pl/userfiles/file/79602150192.pdfIn PDF document text
    • http://lehnerkom.de/images/uploaded/file/wesiwafosagilumozeneko.pdfIn PDF document text
    • http://alexandersorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/taxelatoloremogimeg.pdfIn PDF document text
    • https://digitaluzaktanegitim.com/calisma2/files/uploads/goruvenunavixiw.pdfIn PDF document text
    • https://picinterior.com/ckfinder/userfiles/files/boxupajipuvafoxufor.pdfIn PDF document text
    • https://civilkontroll.hu/uploads/file/dotexumoraziserowurosupe.pdfIn PDF document text
    • http://101-games.ru/images/uploads/files/12610816175.pdfIn PDF document text
    • https://tahitotfalu.hu/ckfinder/userfiles/files/niziwuzowipufotixufonofa.pdfIn PDF document text
    • http://montoaneli.com/ckfinder/files/rumiguvoduju.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/51789480161.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=platinmods+pubg+freePDF 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_off0000b915.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB915 11080 bytes
SHA-256: c88735ee50297e8a842b9ba3e7d5825f348b40dc1adf9281dce46811fd050672
font_01_sfnt_off0000d273.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD273 17176 bytes
SHA-256: 7692199879131e10ac41a4b8b2f1f18d7f5bc765dde8e3b93cadc05bcac8b0d5
font_02_sfnt_off0000ff3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF3A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1