Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb29681153fe0adf…

MALICIOUS

PDF

76.5 KB Created: 2021-09-20 18:52:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 3dbfa567aa504c13b90f842e83951e80 SHA-1: cf45e12d200d673c3f6e0573da68121ef150fac9 SHA-256: cb29681153fe0adf248850a3489dbce2804228662231c67f0b3aea11e6ed8502
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF that contains numerous embedded URLs, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. The PDF structure and URL patterns suggest it's designed to lure users to external sites, potentially for credential harvesting or further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://synerhu.ru/uplcv?utm_term=ace+fighter+download PDF link annotation
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cba5bd3fe2---tenudetabulilukezew.pdfIn PDF document text
    • http://lohoithaiduong.com/uploads/files/91329969016.pdfIn PDF document text
    • http://uekekb.ru/!upload/files/84828395131.pdfIn PDF document text
    • https://buffinvestment.com/upload/ckfinder/files/32752142670.pdfIn PDF document text
    • http://jshanwoo.com/ckfinder/userfiles/files/99190806956.pdfIn PDF document text
    • http://k12kos.com/ckfinder/userfiles/files/fekifo.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613422020bbb9---daxuwiwepisusibofitenizi.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/161381734cc128---55481584369.pdfIn PDF document text
    • http://xn----9sbbnbtte4cyg.xn--p1ai/ckfinder/userfiles/files/72787485766.pdfIn PDF document text
    • http://dreamsurgeryen.net/ckupload/files/27764179277.pdfIn PDF document text
    • https://hunde-katzen.at/soubory/79869649118.pdfIn PDF document text
    • https://autoteam.in/ckfinder/userfiles/files/zobukaserikamepukafa.pdfIn PDF document text
    • https://napraforgohotel.hu/upload/file/nukuxewezetegodezaxadi.pdfIn PDF document text
    • http://oletrans.sk/editor_uploads/files/57031561442.pdfIn PDF document text
    • http://thuexe7cho.vn/upload/files/3666979778.pdfIn PDF document text
    • https://aristi-trap.com/upload/users/files/xobovojetazuxiveneduwop.pdfIn PDF document text
    • http://baozhaopharm.com/upload/files/mefesizapenokevuv.pdfIn PDF document text
    • http://thestarbusan.com/FileData/ckfinder/files/20210914_DC2677367CDCA2A8.pdfIn PDF document text
    • http://hennel.hu/sources/elemek/file/40060837366.pdfIn PDF document text
    • https://toananhmedical.com/uploads/files/74012138018.pdfIn PDF document text
    • https://efnnma.org/files/file/46922978634.pdfIn PDF document text
    • https://whitesal.com/data/images/file/7287_20210916125724.pdfIn PDF document text
    • http://getsolarny.com/userfiles/file/24091712370.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/161315c084216b---lemetudisavuxa.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://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_off0000ca8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA8B 18108 bytes
SHA-256: 0ed8bf5d85b5bcc1cd0d7af5254ef96662a71bc0eed6df921d5d67f5dac08d4c
font_01_sfnt_off0000f92e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF92E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011145.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11145 10652 bytes
SHA-256: a32835f115fe5232a5a7f263996e298359ba9db5980e06e2248a57a81b1e05b1