Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8f967e478ba9c65…

MALICIOUS

PDF

86.5 KB Created: 2021-09-14 13:59:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c50aaa7c36d908c56e734f368ec861a8 SHA-1: 527df772cfcd6139c381fa2456b50781dca1b3bd SHA-256: d8f967e478ba9c6586bd40aed03dc462e4c81ad6f508108fb98130239efad6ff
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, with several heuristics indicating it functions as a link farm hosted on potentially compromised or disposable domains. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the nature of the links and the high detection scores point towards a malicious document designed to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 http://cyklo-sport-servis.cz/UserFiles/File/46957332276.pdf In PDF document text
    • http://mai-colle.jp/userfiles/file/musasunefaposatodewuton.pdfIn PDF document text
    • http://optimaglobal.net/ckupload/files/27375303247.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613569a79091d---muloj.pdfIn PDF document text
    • https://residenciasanamaro.es/userfiles/files/bivow.pdfIn PDF document text
    • http://samtekelektrik.com/files/zolasogoxe.pdfIn PDF document text
    • https://balticstroy.com/uploads/files/rabijozetavefawav.pdfIn PDF document text
    • https://www.piramideidiomas.com/ckfinder/userfiles/files/kanufiwovisegimirukixe.pdfIn PDF document text
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fc96e18854---25804621309.pdfIn PDF document text
    • https://goez3.com/10005001208290177/ckfinder/userfiles/files/sejiwukorefudaxubabi.pdfIn PDF document text
    • http://htwy.com/upload/file/544141783.pdfIn PDF document text
    • http://sharon-barron.com/userfiles/files/98257734807.pdfIn PDF document text
    • https://solarconsulting.org/wp-content/plugins/super-forms/uploads/php/files/9b93b67cabca8a05ca023fd9ed52696c/1175519828.pdfIn PDF document text
    • http://nwatchonline.net/userfiles/file/52282089678.pdfIn PDF document text
    • http://metabolit.ru/files/file/31007309217.pdfIn PDF document text
    • http://irodaszer.lukinserv.hu/file/13430985617.pdfIn PDF document text
    • https://volpatoebrum.com.br/_common/admin/scripts/ckfinder/userfiles/files/91614923483.pdfIn PDF document text
    • http://almar-bus.pl/userfiles/file/mijit.pdfIn PDF document text
    • https://skinrepublic.vn/webroot/img/files/82118259298.pdfIn PDF document text
    • http://riph.pl/userfiles/file/62217714234.pdfIn PDF document text
    • http://cnmrobotics.com/files/files/60130072008.pdfIn PDF document text
    • http://yomamasushitogo.com/uploads/files/nupexixaw.pdfIn PDF document text
    • http://www.greddy.com/admin/common/ckfinder/userfiles/File/rakaduxopikewiwobev.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16133b626eb8e5---xisosomu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=update+gradle+version+in+projectPDF 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_off0000e944.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE944 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010156.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10156 18988 bytes
SHA-256: ed2df353c6940243bdc92db1442fe05d21dbc8aa49f7cd8b73f8985a8d298099
font_02_sfnt_off0001337b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1337B 10892 bytes
SHA-256: 650a0094459d564b1d31346c5510f9afbe25d26e492a208c87fbd1b1c82fdd19