Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a15555cf3798d8a…

MALICIOUS

PDF

81.1 KB Created: 2021-09-15 20:48:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4fbc06f69f3be1abd2f22d99bc13b4ef SHA-1: fe1769d388e67dc601dcfc300bc54edde77a4694 SHA-256: 3a15555cf3798d8a6b880248991dc86c379d8d9cad9b7cf6ae7dd3bfcf775b94
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, with heuristics indicating it is a link farm pointing to compromised WordPress uploads and disposable hosting. The embedded JavaScript stream, while not directly analyzed for malicious intent, is a common vector for further exploitation in PDF documents. The numerous URLs suggest a campaign to lure users to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://philabc.ru/uplcv?utm_term=all+phrasal+verbs+in+english+pdf
    • http://flagrant-desir.com/userfiles/file/340206587.pdf
    • http://wmasgroup.com/userfiles/file/86287456362.pdf
    • http://p-itos.net/admin/userfile/image/file/netodapewuxosupibuwel.pdf
    • https://radiosmile.hu/upload/file/gadozuvekiwarefofi.pdf
    • http://sevennews.com.br/ckfinder/userfiles/files/24715788732.pdf
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/161404a2659885---37008213485.pdf
    • http://aedjtjdshbf.pretty-match.com/upload/files/mufotoganezulozemedet.pdf
    • https://myparrotfood.com/user_files/files/wegojuxil.pdf
    • https://aznamaste.com/ckfinder/userfiles/files/dujimuwefoduv.pdf
    • https://insights3.com/wp-content/plugins/super-forms/uploads/php/files/ff00e7b95fe880a6ff502a6182e4130e/91274877879.pdf
    • http://canvangdientu.com/images/file/18909184275.pdf
    • http://xn----ctbguteehkho5h.xn--p1ai/ckfinder/userfiles/files/devazaxujesofuwixeje.pdf
    • http://micruts.org/userfiles/file/katol.pdf
    • http://familiegravesen.dk/ckfinder/userfiles/files/jezonurefepemixodogaxexol.pdf
    • http://educasters.co/ckfinder/userfiles/files/zovosafa.pdf
    • http://swaving-stalinrichting.nl/ckfinder/userfiles/files/69558543654.pdf
    • http://xn--lv0az70cxar.tw/uploads/files/202109050256173661.pdf
    • http://onsijsselstein.nl/userfiles/files/7951252425.pdf
    • http://chieusangducphat.com/uploads/userfiles/file/togebi.pdf
    • http://louisefarmersmith.com/admin/ckeditor/ckfinder/userfiles/files/20135731274.pdf
    • https://csam-villepinte.org/uploads/images/file/25216708536.pdf
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/1739fe7aece67f5aba7a0de28b6b005f/pekonoremuxotimaxim.pdf
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613946eb2a6e8---43541980496.pdf
    • http://cps-mbstu.edu.bd/app/webroot/js/ckfinder/userfiles/files/tujavawoxumasusorovosikev.pdf
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f6bd0a24ce---wefozewamo.pdf
    • http://dataprint.ie/uploads/file/88668507775.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d7e1.bin
eab512225199abfea27321e6d94ac74127ab23f6865f99b874595ebe40a45997
pdf-font-stream PDF embedded font (sfnt) at offset 0xD7E1 10744 bytes
font_01_sfnt_off0000f01d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF01D 16792 bytes
font_02_sfnt_off0001082f.bin
a6a8de6b9431cec6edf16f06e06a0d036bf11eea73b0f842c138d7afdf854d3b
pdf-font-stream PDF embedded font (sfnt) at offset 0x1082F 18268 bytes