Malicious PDF — malware analysis report

Static analysis result for SHA-256 57ddafd1e9b92578…

MALICIOUS

PDF

75.4 KB Created: 2021-09-25 23:09:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 2451bd7de827d5e27fed9fdda4f3264e SHA-1: 5a2f1af61fe89c90aa542aa31d1cb98fa859aea6 SHA-256: 57ddafd1e9b92578100a35ce5d3267cb7c76f9327ba0475940e76b3cd6871f5c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various PDF files hosted on different domains, indicative of a link farm. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic and the high number of unknown reputation URLs strongly suggest this malicious intent. While no scripts were explicitly extracted, the ML classifier and ClamAV detection confirm the malicious nature of the PDF, likely serving as a lure or a distribution point for further threats.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://tokyoracing.hu/userfiles/file/serabore.pdf In PDF document text
    • http://saigondome.com/uploads/userfiles/file/kaberonifiruda.pdfIn PDF document text
    • https://ka-base.no/images_students/files/gunujaxefugoziremajos.pdfIn PDF document text
    • http://cuboni.com/uploadfile/hong202109111044354547.pdfIn PDF document text
    • http://burelomdo.com/ckfinder/userfiles/files/63583129176.pdfIn PDF document text
    • http://lifebeachvilla.com/uploads/image/files/gotodamopeb.pdfIn PDF document text
    • https://permargi.com/files/galeria/files/47384367737.pdfIn PDF document text
    • http://bienbao.net/uploads/files/46305552365.pdfIn PDF document text
    • http://szermgrt.hu/uploads/ckfinder/userfiles/files/19106016337.pdfIn PDF document text
    • http://asja.ua/userfiles/file/43042717099.pdfIn PDF document text
    • https://nhatngudongkinh.phapluatvietnam.com/upload/ckupload/files/tinutomitexejasuj.pdfIn PDF document text
    • http://agriturismolataggiasca.eu/userfiles/files/81364448849.pdfIn PDF document text
    • http://analogsys.com/uploaded/file/1595827019614e2e267c859.pdfIn PDF document text
    • http://cherriestattoo.com/ckfinder/userfiles/files/50704844017.pdfIn PDF document text
    • http://special-pharma.com/upload/files/filipipivef.pdfIn PDF document text
    • https://h1t-url12shio-turbo.com/contents/files/70808836949.pdfIn PDF document text
    • http://mikomisushi.com/uploads/files/11737681942.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/a6968ea4b029145a962f63078a6799d9/60092409483.pdfIn PDF document text
    • https://palet-school.com/files/files/zafetowirulituzosu.pdfIn PDF document text
    • http://xn----7sbbbizu2bxaod.xn--p1ai/userfiles/file/49170072641.pdfIn PDF document text
    • http://honda-vo.com/upload/file/30257776443.pdfIn PDF document text
    • http://lexxyin.net/files/fckeditor/file/xiluzuvakejexibuvodafe.pdfIn PDF document text
    • http://finchamauto.com/pics/66145314042.pdfIn PDF document text
    • http://www.aragonemprendedor.com/userfiles/files/feropereg.pdfIn PDF document text
    • http://kystar.net/filespath/files/20210904230233.pdfIn PDF document text
    • http://www.mostenpo.jp/userfiles/files/87736545902.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=kaneki+ken+wallpaper+androidPDF 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_off0000bcad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCAD 19496 bytes
SHA-256: e1d1cb0fdefbfaa94dcb5b1d16aab728ba880aaeabdfc70f5429a0b45c37844b
font_01_sfnt_off0000ef45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF45 10288 bytes
SHA-256: caf700dd359166c863ef2bcbed414ad402a1e33c777a084bfd2dbeb2654eb367
font_02_sfnt_off00010682.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10682 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1