Malicious PDF — malware analysis report

Static analysis result for SHA-256 b19f5d7fd4ff9d9a…

MALICIOUS

PDF

71.8 KB Created: 2021-08-24 23:51:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 7fdd9a1494e842720d1e3b8a7f217ae1 SHA-1: 404d57c3c01f26991f40e45ecb185b876db7801d SHA-256: b19f5d7fd4ff9d9ac57005c05df01b15831c94e8906d588cad4d66ec8d7ce544
156 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to multiple compromised WordPress sites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking clear user-facing content but containing embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/9c6a9et0gojlq9ck2uamg7f76o/6196492118.pdf In PDF document text
    • http://e-skala.pl/userfiles/file/15933150909.pdfIn PDF document text
    • https://argentinaproduct.com/ckfinder/userfiles/files/97751696255.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160f2da1669585---32934246811.pdfIn PDF document text
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1610329fcca725---tugefeveduwen.pdfIn PDF document text
    • http://promador.pl/userfiles/file/paluboboloreju.pdfIn PDF document text
    • http://tcurryproperties.com/konadnew/userfiles/file/9528553902.pdfIn PDF document text
    • http://gocep.org/data/userfiles/files/70412137365.pdfIn PDF document text
    • http://juha.be/_files/file/47785932349.pdfIn PDF document text
    • http://longarmquiltacademy.com/fckeditor/userfiles/file/mitaxunawanojajeriv.pdfIn PDF document text
    • http://thetuckerfamilyreunion.com/clients/67950/File/63356172932.pdfIn PDF document text
    • http://gamebonda.com/ckupload/files/movemavokusataja.pdfIn PDF document text
    • http://1night2day.com/ckupload/files/42278296654.pdfIn PDF document text
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/u56t3s1ofbmes33me4lorvc216/zelunuwapipofujan.pdfIn PDF document text
    • https://momentous-inst.com/uploads/image/files/48133932595.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a6e3222bcad---rijupilegebixaxe.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a0f9f77cedd---mujul.pdfIn PDF document text
    • http://werder-ritter.de/UserFiles/File/346425680.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/phn5pmb5frnsd0lvrs0mtderm7/roxikexotebebogeto.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bf948f72ae8---gebonizizebe.pdfIn PDF document text
    • http://bloemenwinkelindex.nl/images/uploads/ronupifunonutaxoxa.pdfIn PDF document text
    • http://bvmnotarissen.nl/app/webroot/files/ckeditor_files/files/bipakabazabex.pdfIn PDF document text
    • https://zivotzaokny.eu/res/file/bidajojoro.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160870d961afe8---9416085915.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=kg+to+forcePDF 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_off0000bd3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD3E 9932 bytes
SHA-256: f5676650eb614f1fb60b5af3d9ef3a585f614a1ad59afe1d64ae32b90cb49628
font_01_sfnt_off0000d350.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD350 14760 bytes
SHA-256: b9540f302bce4e6181112cf15b75215491e79d1b233d429aefab9c803fca0bd9
font_02_sfnt_off0000f894.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF894 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1