Malicious PDF — malware analysis report

Static analysis result for SHA-256 35fa87be233b0f51…

MALICIOUS

PDF

89.4 KB Created: 2021-07-15 16:46:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: c26d686bfac8ae5f8efe465bfb5630dd SHA-1: cd93b0e8e7924b370f0b4a172cb75cc5ff47a15d SHA-256: 35fa87be233b0f51961d8adfc22f3a06219143f90674d01b9f45dee91a17c07d
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier indicating a high probability of maliciousness. It contains a link farm pointing to numerous external URLs, many hosted on compromised WordPress sites, suggesting an attempt to redirect users to phishing or malware distribution sites. The document body is heavily obfuscated and unreadable, but the presence of external links and the overall heuristic profile strongly indicate a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • 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.
  • 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://synerhu.ru/uplcv?utm_term=nike+donations+request PDF link annotation
    • https://aydin-elektrik.com/resimler/files/86104256428.pdfIn PDF document text
    • https://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/5f3b0dcd65c8639d15a2348c247988d5/lujonaligimix.pdfIn PDF document text
    • https://mut-zur-veraenderung-hambuch.de/userfiles/file/19805517267.pdfIn PDF document text
    • http://www.rkcomdesignservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092656b09589---34558690340.pdfIn PDF document text
    • http://auburn-properties.com/userfiles/files/jidatuwogag.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/160754879d6d11---dotowuj.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/jvq6slheaae1rm6ebn9g9ilu8t/81682047303.pdfIn PDF document text
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/bbd1el66ifi717jb1m9d2nprgr/jebizet.pdfIn PDF document text
    • http://siembra.me/uploads/files/26512134439.pdfIn PDF document text
    • https://btsmstlucia.com/atomicsteps/upload/userfiles/file/51033191093.pdfIn PDF document text
    • https://fid-data.fr/app/webroot/uploaderfiles/34846537365.pdfIn PDF document text
    • https://www.kbstephens.com/wp-content/plugins/super-forms/uploads/php/files/50f2b14b06b09460e4659eb90d063d24/54389164872.pdfIn PDF document text
    • https://koratspring.com/upload/file/20086285677.pdfIn PDF document text
    • http://arqing.es/ckfinder/userfiles/files/82264779221.pdfIn PDF document text
    • http://angelojrobles.com/admin_initial_test/userfiles/file/welit.pdfIn PDF document text
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609053b0029da---8611861646.pdfIn PDF document text
    • http://zonazero.es/userfiles/file/kexoramewezew.pdfIn PDF document text
    • http://s292376414.onlinehome.fr/datas/imgmail/file/88772386117.pdfIn PDF document text
    • 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_off0000fab1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAB1 17580 bytes
SHA-256: 70b1a662bc3728939e704efc48d8a404b19d31385e70402701090218d5bceccc
font_01_sfnt_off00012906.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12906 10508 bytes
SHA-256: 9c40d802319491d3af74b599d172c956e750a36ea0b892e2bfe95cb04653ebfb
font_02_sfnt_off000140e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x140E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1