Malicious PDF — malware analysis report

Static analysis result for SHA-256 caa16c217f91cf2e…

MALICIOUS

PDF

71.5 KB Created: 2021-09-17 09:36:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 48a8a533c409b78f66f8dc4f7b0bc816 SHA-1: b576b5d0d53659a87444d356c63a270164c71366 SHA-256: caa16c217f91cf2e5e8640d15bf8a48dee5c053e5ac7fd3bca70dffc5a3bdb30
126 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. Multiple embedded URLs point to unknown or potentially malicious domains, suggesting an attempt to redirect users to harmful content. The PDF structure and the presence of numerous links on disposable hosting reinforce the conclusion that this is a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://grupo-kayros.com/userfiles/file/nonofuxikaresawutaboloni.pdf In PDF document text
    • http://thoitrangvabaoho.com/Images_upload/files/46480215755.pdfIn PDF document text
    • https://bahispesinde.com/gnc/veri/_files/65216013992.pdfIn PDF document text
    • http://protok.pro/upload/files/tegikekexuzopoxuguj.pdfIn PDF document text
    • http://zs-oilfieldequip.ru/d/files/xofolatazutubemu.pdfIn PDF document text
    • http://mosjob.ru/images/file/fofilurelamotubo.pdfIn PDF document text
    • https://lanjutpt1.com/contents/files/11679067145.pdfIn PDF document text
    • http://imobilestore.de/userfiles/file/75494407573.pdfIn PDF document text
    • https://maximatrimony.com/ckfinder/userfiles/files/dozoladalanib.pdfIn PDF document text
    • http://dainichiji.com/upload_ckr/files/popanomimunarefu.pdfIn PDF document text
    • https://markyatirim.com/resimler/files/goxelemeru.pdfIn PDF document text
    • http://nurugelexport.com/ckfinder/userfiles/files/83050745057.pdfIn PDF document text
    • http://dakdekkersindex.nl/images/uploads/gavoki.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/1613ecee7b25ab---wurozogogemazide.pdfIn PDF document text
    • http://architettotoma.it/userfiles/files/11928749301.pdfIn PDF document text
    • https://franchiseharbor.com/files/files/dujok.pdfIn PDF document text
    • http://xn--j1aii.su/userfiles/file/29969175721.pdfIn PDF document text
    • http://fujavietnam.com/images/Download/68882179576.pdfIn PDF document text
    • https://pioneerlift.com/upfiles/editor/files/wavezedofajesobo.pdfIn PDF document text
    • http://phaptangpgvn.net/app/webroot/upload/files/17417001415.pdfIn PDF document text
    • https://www.domaine-vrignaud.com/ckfinder/userfiles/files/40167842637.pdfIn PDF document text
    • http://china-engine.net/ckfinder/userfiles/files/66114281289.pdfIn PDF document text
    • http://bnblspecialities.com/userfiles/files/xofugutomukonawapafigoxad.pdfIn PDF document text
    • http://aviatechinform.ru/sadm_files/73215857337.pdfIn PDF document text
    • http://boldogelet.hu/media/50377017416.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=shubh+mangal+zyada+saavdhan+torrentPDF 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_off0000b566.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB566 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cd78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD78 15868 bytes
SHA-256: 238b9e3ae55c6d89f96ea47baf76b5f4f63bbfb32f9497cb182954c24080167d
font_02_sfnt_off0000f65e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF65E 11160 bytes
SHA-256: 67642cdae4ab7f00e7d5fa6e9a4d82439434873873cc273c2ad738bfc8d19387