Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f3ed7d851837230…

MALICIOUS

PDF

84.4 KB Created: 2021-09-13 20:16:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: 89c200e063d5136ec650210426f8b093 SHA-1: 1683c5e3a27a3e5b57d701ef625ae6331f6b5c0e SHA-256: 3f3ed7d851837230e1048ab7196d44ca21af31850f00e6f27fa19e96f1a5bc11
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a high number of embedded URLs pointing to various domains, many of which are likely disposable, indicating a link farm or phishing distribution mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, noting a large number of links on disposable hosting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://barrier.exma.cl/ckfinder/userfiles/files/keguriwila.pdf In PDF document text
    • https://horgaszvelem.hu/ckfinder/userfiles/files/nogorarexis.pdfIn PDF document text
    • https://accuratesearch.com/userfiles/file/45989424022.pdfIn PDF document text
    • http://kutyasturak.hu/images/files/kizowusigedozirasogoregi.pdfIn PDF document text
    • http://islenapuntos.com/campannas/file/71154227229.pdfIn PDF document text
    • http://bayanairag.com/uploads/userfiles/files/paxowifolavese.pdfIn PDF document text
    • http://termosystem.pl/userfiles/file/70516867651.pdfIn PDF document text
    • http://www.frank-diagn.hu/userfiles/files/manogagipafup.pdfIn PDF document text
    • http://tk-weld.com/images/library/File/mazevi.pdfIn PDF document text
    • http://sksound.com/userfiles/file/jurejeforu.pdfIn PDF document text
    • http://www.chiringuitomediterraneo.com/ckfinder/userfiles/files/zerubunuluzedigamedawas.pdfIn PDF document text
    • https://em.heephong.org/ethnicminorities/cmsadmin/ckfinder/files/todosuzedivikesubi.pdfIn PDF document text
    • http://bajcsidavidfoto.com/_user/file/3280178885.pdfIn PDF document text
    • http://ck-buhgalter.ru/userfiles/file/xifemawobi.pdfIn PDF document text
    • https://www.info-service.com.tw/plugin/ckeditor/ckfinder/userfiles/files/52932960752.pdfIn PDF document text
    • http://jysfh.com/upload_fck/file/2021-9-13/20210913110218983686.pdfIn PDF document text
    • http://ainut.fi/userfiles/file/65205286518.pdfIn PDF document text
    • http://www.egavilanes.com/ckfinder/userfiles/files/tuzinob.pdfIn PDF document text
    • http://sklenicky-obchod.cz/web/admin/fckeditor/userfiles/file/wenozipizigoman.pdfIn PDF document text
    • https://firsatpin.com/calisma2/files/uploads/89456726302.pdfIn PDF document text
    • http://hyundaidongdo3s.com/images/files/69565428356.pdfIn PDF document text
    • https://sushixusa.com/userfiles/files/fekar.pdfIn PDF document text
    • https://4cmedica.com/ficheiros_upload/file/84662845880.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=most+venomous+jellyfish+in+the+worldPDF 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_off0000e53a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE53A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fd51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD51 10948 bytes
SHA-256: c08286e6e052e5f89488a0c85815c71f74fbde73339af5f39096869d8276a4fa
font_02_sfnt_off00011685.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11685 17672 bytes
SHA-256: fdc3caeed53f50c3a1b7e70f93a07efdb38a6c0f8d82666aa8518dde4e035228