Malicious PDF — malware analysis report

Static analysis result for SHA-256 663d2961bc1fbd4d…

MALICIOUS

PDF

81.2 KB Created: 2021-09-24 00:20:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c0ba7cc684c3babd81b524494d45a459 SHA-1: f84de34fe65bfa961a439b56f6d20ee785744976 SHA-256: 663d2961bc1fbd4d00dcf1d44e3c7066999694bae07d4b28ddf8b95a6afa2384
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, with several pointing to suspicious or unknown domains, indicating a likely phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were directly extracted, the PDF structure and link farm heuristic point towards a common tactic of directing users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://kfk-dekoration.dk/images/uploadedimages/file/piditegavelokosid.pdf In PDF document text
    • https://arch.ua/ckfinder/userfiles/files/wunufozusufe.pdfIn PDF document text
    • http://cen7dias.es/userfiles/files/famaxukizu.pdfIn PDF document text
    • http://dj-maily.com/uploads/pages/files/59646499426.pdfIn PDF document text
    • http://ukwoodrecycling.com/userfiles/files/galilupedakafexux.pdfIn PDF document text
    • http://ulv-fogger.es/d/files/73694099576.pdfIn PDF document text
    • http://elfobchod.cz/foto/Image/file/vurukafasazixorakizigeso.pdfIn PDF document text
    • http://ambulatorioveterinariovianello.eu/userfiles/files/69312518507.pdfIn PDF document text
    • http://systemsbiology.at/uploads/assets/file/4278801408.pdfIn PDF document text
    • http://lovesushiscv.com/uploads/files/72077506940.pdfIn PDF document text
    • http://hidropro.hu/upload/60243500870.pdfIn PDF document text
    • http://www.amedna.com/userfiles/files/21693722574.pdfIn PDF document text
    • https://lexcyberia.com/userfiles/files/zivesujowirino.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/1fb2e22490aebc3f3680c58e20fc7554/beguvizagap.pdfIn PDF document text
    • http://stickers-moins-cher.com/userfiles/stickers-moins-cher.com/file/84603949434.pdfIn PDF document text
    • http://nsmpublicschool.org/slbdavbatala/userfiles/file/tepedesamasofexipolubun.pdfIn PDF document text
    • http://extrastyle.ee/ckfinder/userfiles/files/nifiwotunuvoliwana.pdfIn PDF document text
    • http://studiopiergentili.it/userfiles/files/nopopi.pdfIn PDF document text
    • https://valkexclusief.reviewz.eu/app/webroot/files/userfiles/files/18082341437.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/161346db0e50bc---41512027564.pdfIn PDF document text
    • https://haltia.mx/sii/ckfinder/userfiles/files/72358244289.pdfIn PDF document text
    • http://liebherr-tr.com/userfiles/file/12731582591.pdfIn PDF document text
    • https://aradovan.com/userfiles/file/13946204701.pdfIn PDF document text
    • http://blccy.com/userfiles/files/bijurofofore.pdfIn PDF document text
    • http://myoffice2561.sesao33.net/UserFiles/File/370806589.pdfIn PDF document text
    • https://cursosadistanciayonline.com/medios/files/ginazebuwupawux.pdfIn PDF document text
    • https://szalkasszorutacskok.hu/app/webroot/files/content/files/nalunotedotibuwomaxo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=nexus+7+android+autoPDF 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_off0000da76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA76 17408 bytes
SHA-256: 9665c93fbbd9e9714cd5e88300438368b4df39d81a42e462a8a94cd565575b4e
font_01_sfnt_off00010784.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10784 10424 bytes
SHA-256: e5d648107cc3f2510c0b512766b5d6cec414ee2b589bdf9f6eeed1928b56933f
font_02_sfnt_off00011f5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F5B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1