Malicious PDF — malware analysis report

Static analysis result for SHA-256 d911ec781a3b0dd0…

MALICIOUS

PDF

77.3 KB Created: 2021-09-13 09:54:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 95a08641f57da0a05f81dae80744fb8d SHA-1: 4571f9fab5f0868a3d4367544a9ffba1bec5451b SHA-256: d911ec781a3b0dd0c1f04df5cf875f85d60d979e8f27dca438d65a400a017125
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous embedded URLs pointing to external sites, many of which are part of a link farm designed to obscure the ultimate destination. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests a malicious intent to redirect users, likely for phishing or malware delivery. No scripts were extracted, but the PDF structure and embedded URIs indicate a malicious lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://huntic.ru/uplcv?utm_term=kodi+krypton+17.6+apk PDF link annotation
    • https://optimuselearningschool.com/learning/site/images/uploadfiles/jipoforafaneluxomidodo.pdfIn PDF document text
    • http://studioingegneriavaragnolo.com/userfiles/files/jekifazurakukupal.pdfIn PDF document text
    • http://pensionpoint.cz/userfiles/files/wumipufikodeloginomumita.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613db9165204a---39288908238.pdfIn PDF document text
    • http://mediaworld.pro/ckfinder/userfiles/files/xulanufisimovun.pdfIn PDF document text
    • http://grandwatergatehotel.com/upfile_hotel/files/73291317423.pdfIn PDF document text
    • http://aj-freight.com/ckfinder/userfiles/files/96185837847.pdfIn PDF document text
    • http://guchen.ru/d/files/62102976187.pdfIn PDF document text
    • http://agcslohian.com/userfiles/file/18920722980.pdfIn PDF document text
    • http://holdemigny.fr/ckfinder/userfiles/files/72283431307.pdfIn PDF document text
    • http://traktor-tv.de/sites/default/files/file/risabedigesipezoxugo.pdfIn PDF document text
    • http://naoshima-habitant.com/images/blog/file/91178024324.pdfIn PDF document text
    • http://gaia-onlus.org/userfiles/file/wemapusejipatavibexe.pdfIn PDF document text
    • http://wirheiraten.de/images/file/91961749412.pdfIn PDF document text
    • http://gtlitalia.com/userfiles/files/6641309473.pdfIn PDF document text
    • http://energosol.pl/images_cms/file/linop.pdfIn PDF document text
    • http://terralis.net/catalogue_dynamique/file/buxirefimowo.pdfIn PDF document text
    • http://scenekunstskolen-efteruddannelsen.dk/ckfinder/userfiles/files/57950835290.pdfIn PDF document text
    • http://www.jasfec.com/imgs/uploads/16679837440.pdfIn PDF document text
    • https://iqmuseum.mn/uploads/files/75031052596.pdfIn PDF document text
    • https://goez3.com/10005001208290177/ckfinder/userfiles/files/nonaxapagaka.pdfIn PDF document text
    • http://sinice-rasy.cz/files/file/xijonusavu.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/denonosajenaviwukokunabez.pdfIn PDF document text
    • http://yogathoitrang.com/quangbasanpham/app/webroot/upload/image/files/31776360591.pdfIn PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/161361fdb07b8c---xanak.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_off0000c410.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC410 10572 bytes
SHA-256: 3bb93e10d8412fe16f687ce1c5ad66e6eb95461dc15919c432df1c56453c713b
font_01_sfnt_off0000dc5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC5F 19488 bytes
SHA-256: ee073c3255046279a178a28710f5e5029e7a5eb586725f5a8b98864f93bbe3c4
font_02_sfnt_off00010f5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F5D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1