Malicious PDF — malware analysis report

Static analysis result for SHA-256 c6b836ebd617d2f4…

MALICIOUS

PDF

86.6 KB Created: 2021-09-18 05:52:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: cd55443815ba465e18a3de4951d8872c SHA-1: f7acc09e3a284a33c9936d3e5e57a8f2de334469 SHA-256: c6b836ebd617d2f4651460b41466044feb8e5e4167a8a36ce9ebe2bf92493643
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of multiple external URIs and link farm heuristics supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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 http://ifaistos.reality.gr/~triantaf/images/file/15672746286.pdf In PDF document text
    • http://mentor-tutor.com/newGroserLikeProject/uploads/files/81415062092.pdfIn PDF document text
    • https://www.htlexpress.com/ckfinder/userfiles/files/20467619569.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613b9450cb231---jewezebox.pdfIn PDF document text
    • http://kronospan-mofa.hu/editor_up/zokaduloz.pdfIn PDF document text
    • http://orchid-daikanyama.com/userfiles/file/33947605571.pdfIn PDF document text
    • http://katour.ru/admin/ckfinder/userfiles/files/tubejerirubotudetevol.pdfIn PDF document text
    • http://siamsankyo.com/Uploads/file/24749611416.pdfIn PDF document text
    • http://biancoacolori.it/userfiles/files/susegupak.pdfIn PDF document text
    • http://cpviettin.com/upload/files/worumiv.pdfIn PDF document text
    • http://dighakanchaninternational.com/FCKeditor/file/zebaliduzurizoditikiwo.pdfIn PDF document text
    • http://studiosiciliani.eu/userfiles/files/10061152877.pdfIn PDF document text
    • http://adamex.ukrkarta.ua/fckeditor/userfiles/file/61443941242.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16131f185442cb---lalawixuzuxoverawexibo.pdfIn PDF document text
    • https://flims.atelierleuthold.ch/userfiles/files/pexubajewelizolutojename.pdfIn PDF document text
    • https://cyklo-wellness-penzion-palice.cz/content/wosaxorabovizetifuguropok.pdfIn PDF document text
    • http://kalkulacka-hypo.cz/userfiles/files/93066499400.pdfIn PDF document text
    • http://xn--80aafbladvtgxneccoge3bt.xn--p1ai/pict/file/wujizugomekiporajedoto.pdfIn PDF document text
    • https://getlovebooks.com/wp-content/plugins/super-forms/uploads/php/files/2564a395b0c3eb3a8065c1bb6997473d/lexovurukefawem.pdfIn PDF document text
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1613da7e597500---sixenogipenezewudaforalev.pdfIn PDF document text
    • https://sbmhavacilik.com/userfiles/file/80155227789.pdfIn PDF document text
    • http://a-aqua.fr/ressource/site-image/files/40723180142.pdfIn PDF document text
    • http://fkjz.cn/upload/files/2021/09/202109162214313110.pdfIn PDF document text
    • http://afro-safari.com/upload/files/74999784047.pdfIn PDF document text
    • https://laser123.com/geektic/files/bamavugepevixugenu.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613530736315b---3267855531.pdfIn PDF document text
    • https://igruppe.no/ckfinder/userfiles/files/1164567355.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=soft+reboot+android+phonePDF 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_off0000ee56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE56 10596 bytes
SHA-256: 3001c8b3d8254bb2185c86c51810ec55e3be911af007449777d50b598391e8db
font_01_sfnt_off00010636.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10636 17668 bytes
SHA-256: 8e2d92f2025745dce028e17b2366d6c88635f80246efa7cdbac588e6d4e2b4cf
font_02_sfnt_off00013475.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13475 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1