Malicious PDF — malware analysis report

Static analysis result for SHA-256 815021fb23f49a99…

MALICIOUS

PDF

81.3 KB Created: 2021-09-23 12:24:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: ad67d9a12f80a86722187d2bfb37680c SHA-1: cd9b16b967937b9b1c2648312ad6e8fd5223a5b3 SHA-256: 815021fb23f49a99d4cebc414743038f2fb5f8e7ec7ead172788c72351f30282
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it's a browser extension installation lure. The PDF contains numerous embedded URLs, suggesting a link farm designed to redirect users to malicious sites. While no scripts were explicitly extracted, the nature of the lure and the detection name 'Pdf.Phishing.Trojan' strongly suggest a phishing or malware delivery attempt, likely involving JavaScript exploitation within the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://dynasty888.com/image/files/20210917_053238.pdf In PDF document text
    • http://mwcapital.net/ckfinder/userfiles/files/57803382983.pdfIn PDF document text
    • https://bak.vn/upload/files/65558229587.pdfIn PDF document text
    • http://daiichihr.com/uploads/news_file/nudonumelomarageketetima.pdfIn PDF document text
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/10a8d2aef676705e83738d6ded6cc7a4/36592534866.pdfIn PDF document text
    • https://stvorki.ru/files/file/rodonuzogogofimefotone.pdfIn PDF document text
    • http://elsped.hu/files/file/67752454953.pdfIn PDF document text
    • http://droneducational.com/admin/userfiles/file/nozakokatexotubimiluwumuf.pdfIn PDF document text
    • http://dreiseengrundschule.de/files/kobodigudaxasubufekofo.pdfIn PDF document text
    • https://unitedfightalliance.jordanadams.com/ckfinder/userfiles/files/pofegakejobakewurajapa.pdfIn PDF document text
    • http://entryexpress.online/chapter_images/files/44731422803.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/161425f443d811---38147744094.pdfIn PDF document text
    • http://rheumatology.institute/upload/content/file/586359747.pdfIn PDF document text
    • http://emrc.ie/upload/imagecontent/file/45811892354.pdfIn PDF document text
    • http://ncdesign.it/userfiles/files/mefonaregelanid.pdfIn PDF document text
    • http://bonfiremadigan.com/uploads/fckeditor/file/20089444731.pdfIn PDF document text
    • http://short-story.ru/upload/file/dikewadeniranejekemurolu.pdfIn PDF document text
    • https://adasms.fr/userfiles/file/80162342357.pdfIn PDF document text
    • http://travel-door.com/userfiles/file/1879243432.pdfIn PDF document text
    • https://baobiachau.com/luutru/files/nevajesesanakumajax.pdfIn PDF document text
    • http://alacarte-design.de/userfiles/file/fitosokanifabolazapezi.pdfIn PDF document text
    • http://phuketdriveschool.com/userfiles/file/bifusisurofonurug.pdfIn PDF document text
    • https://brihat-group.com/assets/userfiles/files/besozojupojutejogosok.pdfIn PDF document text
    • https://www.domaine-boussard-chablis.fr/ckfinder/userfiles/files/94760518184.pdfIn PDF document text
    • https://gabconstruction.com/ckfinder/userfiles/files/duturasafetajote.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=houses+for+20k+bloxburgPDF 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_off0000d8da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8DA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f0ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0EC 17932 bytes
SHA-256: 9afc979bef993ca38ecc8dfe91e7f77dc32fe55df485ee6dee9712dafa7f8b41
font_02_sfnt_off00011f5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F5D 10600 bytes
SHA-256: f13d8d68bf1ee59cad6de520658ad6b39a40ad16ab0b5cd935d72d5962062ac2