Malicious PDF — malware analysis report

Static analysis result for SHA-256 a236cd21973407e8…

MALICIOUS

PDF

81.2 KB Created: 2021-08-10 06:56:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: a4362657e22c215ca41d23b5aa6b85f8 SHA-1: 5a02ae22b07e74f0dbeb53eab3c66b6ac203f33f SHA-256: a236cd21973407e8576909a9cfec6b4f72e58d968e761d59310aba17e30582bd
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file exhibits characteristics of a link farm, with numerous embedded URLs pointing to various websites, some of which appear to be compromised. The ML classifier strongly indicates maliciousness. While no scripts were directly extracted, the structure and numerous external links suggest an attempt to redirect users to potentially harmful content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 5

  • 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://www.alphaveneers.com/wp-content/plugins/super-forms/uploads/php/files/1e0f4d33587d94bd863b3d614aafcdeb/47516674021.pdf In PDF document text
    • https://xistenze.com/files/files/tusanaviviva.pdfIn PDF document text
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098441392c97---35160815653.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1609c10ff1fb89---xiliwojamikebiril.pdfIn PDF document text
    • http://nsmpublicschool.org/slbdavbatala/userfiles/file/gataxirizodaw.pdfIn PDF document text
    • https://mojer.bg/files/mawiwodet.pdfIn PDF document text
    • https://balajitutorial.com/admin/userfiles/file/birojus.pdfIn PDF document text
    • http://tai-yang.tw/taiyang/upload/file/94367883419.pdfIn PDF document text
    • http://wuxihemei.com/ckfinder/userfiles/files/20210717_164205.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607c1f69bf9a3---vufokomobusivoledirufutud.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/1lt1k5aerd688ia3hvj26hr4a3/niruvofagu.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b76c6014c16---moromuwuguwewoxasexibavet.pdfIn PDF document text
    • http://funperm.ru/content/file/puvobofadasan.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3dd0c5150e---57548818248.pdfIn PDF document text
    • http://wghsclassof69reunion.com/clients/b/b3/b33699c65747f61a54cd06c2fab73d22/File/vuvap.pdfIn PDF document text
    • http://ddmlife.com/ckupload/files/37982562949.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/40494564572.pdfIn PDF document text
    • http://supermarketdv.ru/files/file/rutubazujipudamajixiruz.pdfIn PDF document text
    • http://nwatchonline.net/userfiles/file/91167098067.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/s28r3n1ecomv19qvgb9toidk1r/65106352988.pdfIn PDF document text
    • https://singaporenotarypublic.com/wp-content/plugins/super-forms/uploads/php/files/ba0bec29967d0f640fe30d0394387d6e/83407896438.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/a272fe7882797da45ab6ef9e7513ac43/fukodex.pdfIn PDF document text
    • http://studiotecnicoprato.eu/userfiles/files/55774496573.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=norton+intro+to+literature+13th+editionPDF 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_off0000d9cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9CF 10480 bytes
SHA-256: dbb2b3cf907d7c3a384ed5a51c1d362cfa553dd6cfec4098fef1c8be0d2e5dad
font_01_sfnt_off0000f194.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF194 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000109a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109A6 17520 bytes
SHA-256: 5ce6f43049d0ccf291d1b3e69b78881beb7908303c626bff50622f3fa45395c8