Malicious PDF — malware analysis report

Static analysis result for SHA-256 588bf29c2c5b63e6…

MALICIOUS

PDF

98.9 KB Created: 2021-10-16 05:52:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: de757e677cdf61d80e1f78af6aacee12 SHA-1: 599a6738aefdc88ba197d8c2ffb09f7e494995ed SHA-256: 588bf29c2c5b63e64f651f397feab4e9b833beb4fcff9ad24848b1af3e64813d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. Heuristics indicate it functions as a link farm, pointing to multiple domains, some of which are compromised CMS uploads. The document body is heavily obfuscated and unreadable, suggesting it's designed to hide its malicious intent rather than convey information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://magendans.com/imagefiles/file/79856796255.pdf
    • http://arsvet.ru/img/upload/fisudavebe.pdf
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/bfehl6jb36lrdng7ansqop22hk/96707450656.pdf
    • http://finpacecuador.com/userfiles/file/xopew.pdf
    • https://danielstrehlau.com/userfiles/file/1715643948.pdf
    • http://sarkar.ie/userfiles/file/fumatanezixaxes.pdf
    • http://texinpack.com/uploadfile/file///2021101513251713.pdf
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1614d6ccbd9232---demisariwebisupasovimepo.pdf
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/1613ff5f5cf6ae---22544488092.pdf
    • http://ylgems.com/file_media/file_image/file/nexejovuguwixurukewo.pdf
    • https://tinhhoaxanh.vn/userfiles/file/jijonulejon.pdf
    • http://studioschicchi.eu/userfiles/files/61152470243.pdf
    • https://senarathgroup.lk/assets/media/file/10422492098.pdf
    • http://www.tomasjelinek.com/img/pub/file/dinerol.pdf
    • https://tlproduct.com/userfiles/file/47689365686.pdf
    • http://langeline.com/ckeditor/upload/files/33016671038.pdf
    • http://petraifevronii.ru/ckfinder/userfiles/files/1053096376.pdf
    • http://ekorob.pl/userfiles/file/reralirazijilejux.pdf
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16163733257f0b---5685048676.pdf
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161563a44458ba---fimemukadexipexo.pdf
    • http://am-assets.com/aom/magnolia/userfiles/file/lumikake.pdf
    • http://caopump.com/admin/userfiles/file/39584665085.pdf
    • https://feedproxy.google.com/~r/Gsjc/~3/5bhJmFgkeCE/uplcv?utm_term=these+meaning+in+tamil
    • 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_off00011ab8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11AB8 16792 bytes
font_01_sfnt_off000132cf.bin
ce7f6f4fa2940efaa678599d62786a554d3fdf09535212f5955aa21c9ea69c8d
pdf-font-stream PDF embedded font (sfnt) at offset 0x132CF 10296 bytes
font_02_sfnt_off000149c6.bin
01c7abbc5a5f710ab590feda29205e76964f935bd6c6b6a642ed4afe8e05a882
pdf-font-stream PDF embedded font (sfnt) at offset 0x149C6 21404 bytes