Malicious PDF — malware analysis report

Static analysis result for SHA-256 23cbf36b26ce5554…

MALICIOUS

PDF

76.5 KB Created: 2021-09-27 10:02:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 812fb1b06a1b6a0fe0f67b2fad1bf402 SHA-1: 00c6f91eb4bf7b35212e857b4e54a397dfd97604 SHA-256: 23cbf36b26ce55541f49446c70f56506063cbbe425d2ad91e6a5a9d2d7706c14
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to a link farm, indicating a potential phishing or malware distribution scheme. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM suggests the document is designed to host many links on disposable domains, a common tactic for such attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://tinhdauvietnam.vn/upload/files/sotazovexulisututexegiwud.pdf In PDF document text
    • http://ipceurope.eu/assets/file/tigipuvore.pdfIn PDF document text
    • http://www.bordadoindustrial.com/ckfinder/userfiles/files/90104133231.pdfIn PDF document text
    • https://architektor.ru/uploads/file/38696208511.pdfIn PDF document text
    • http://firmykominkowe.pl/Obrazki/edytor/file/32349257170.pdfIn PDF document text
    • http://decamiones.com/userfiles/file/34703286965.pdfIn PDF document text
    • https://grandiosieventinuziali.it/filesUploads/file/64896448125.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/9aa7729b9eba7fd6c23237b8c8375597/tuven.pdfIn PDF document text
    • http://mskgroup-spb.ru/upload/file/zosorajewobogegaxezufura.pdfIn PDF document text
    • http://saigonford3s.com/uploads/2021-09-16/images/files/10235613926.pdfIn PDF document text
    • http://hanifeugur.com/image/files/91627561462.pdfIn PDF document text
    • https://adamant54.ru/userfiles/files/3272311116.pdfIn PDF document text
    • http://indianapit.thriftstorewebsites.net/flash/indianapit.thriftstorewebsites.net/file/deviwula.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136eab943e6f---20122408714.pdfIn PDF document text
    • http://okna-dvere-online.cz/media/upload/upload/file/vuwadegi.pdfIn PDF document text
    • https://www.bakkersvlaanderen.be/resources/plugins/ckfinder/userfiles/0/files/zatixexukesesebafifu.pdfIn PDF document text
    • http://tokyoto.pl/UserFiles/file/80880853124.pdfIn PDF document text
    • http://www.pacautomarketing.com/file/wisamafi.pdfIn PDF document text
    • http://daehwa.info/uploaded/file/gulek.pdfIn PDF document text
    • https://nikoljski.com/ckfinder/userfiles/files/66247867030.pdfIn PDF document text
    • http://zeroseistudio.eu/userfiles/files/xorabalijupa.pdfIn PDF document text
    • https://superpart.com/files/33456027075.pdfIn PDF document text
    • http://hotdeals24x7.com/ci/userfiles/files/40965004474.pdfIn PDF document text
    • http://saint-party.com/media/file/musoxapa.pdfIn PDF document text
    • http://skalamatbaa.com/userfiles/file/60203014234.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=elementary+linear+algebra+howard+anton+11th+edition+pdfPDF link annotation
    • http://alessandrotria.altervista.org/areap/ckfinder/userfiles/files/29634054946.pdfIn PDF document text
    • 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_off0000c3bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3BF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dbd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBD1 17760 bytes
SHA-256: f617eda4c3f46c53e538619547704cb91af207c7a8523d65f5b699c5e947c40b
font_02_sfnt_off000109e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109E6 11152 bytes
SHA-256: 80ebcc91fc93845fd5ad7fbb205e85ee4cf4bb7a20b2a46aa70d93d5ead3fc1f