Malicious PDF — malware analysis report

Static analysis result for SHA-256 40ee99e735e1a9a7…

MALICIOUS

PDF

82.5 KB Created: 2021-09-07 02:03:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 8e326ae7939b8a1a9a82c0cfea65247a SHA-1: 1b2318879101ceb3947e18137d21343c59517b24 SHA-256: 40ee99e735e1a9a742fbcdc400950048962a6f70a410a84382db23b76d650352
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as 'Pdf.Phishing.Trojan' and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with several URLs pointing to compromised WordPress upload directories and disposable hosting. The document body is heavily obfuscated, preventing analysis of its direct content, but the presence of numerous external links suggests a phishing or SEO manipulation attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://ukdirectremovals.com/wp-content/plugins/super-forms/uploads/php/files/f3adbd15f61b7baf332dca02b3593895/13626274572.pdf In PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/161363fe8b8590---17230394487.pdfIn PDF document text
    • http://dailycan.com/userfiles/files/vojowagolafexoligo.pdfIn PDF document text
    • http://handsonmontessoripk.com/userfiles/files/sukiluk.pdfIn PDF document text
    • https://jurvamartin.com/userfiles/file/figejajij.pdfIn PDF document text
    • http://vodnik48.ru/content/file/8249926512.pdfIn PDF document text
    • http://garantc.ru/userfiles/file/19054433814.pdfIn PDF document text
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/76092729d38097c5279c2b55acba199c/nekewimemowerobezibovin.pdfIn PDF document text
    • http://jandenzobv.com/image_uploads/file/97222317909.pdfIn PDF document text
    • http://kovofilm.cz/userfiles/file/77384410714.pdfIn PDF document text
    • http://mdfgiare.com/upload/files/mumib.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160d205fa5dcd8---87794226162.pdfIn PDF document text
    • https://pima-alarms.net/slicice/file/fuxisewarubudokabodekiko.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6ea63e6026---junekerefasuboxak.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d9fbf5b95ae---kisesu.pdfIn PDF document text
    • http://danielbushreunion.com/clients/41596/File/nupagekezegebujijufumew.pdfIn PDF document text
    • http://studiopedrazzini.eu/userfiles/files/63119224107.pdfIn PDF document text
    • http://15fratrowreunion.com/clients/2/2b/2b18ccadde375fd95e9ac2d5db5aaa67/File/6112560031.pdfIn PDF document text
    • http://jtour.vn/userfiles/file/pujerakezunavinovodokasal.pdfIn PDF document text
    • https://gtnet-engine.com/ckfinder/userfiles/files/19489417344.pdfIn PDF document text
    • https://sedefartphotography.com/resimler/files/61559383401.pdfIn PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/682542bc9a08926cba755f54840ff4c7/nebimev.pdfIn PDF document text
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/c4ojkepea855nccsuq7kmi04vm/10162744967.pdfIn PDF document text
    • http://dobraukraina.org/sites/all/sites/dobraukraina.org/files/tuzosogodajogukeron.pdfIn PDF document text
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/f75e5c9abd35ea99fffc3bf9b5ee6024/59333909178.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=finding+averages+from+frequency+tables+worksheetPDF 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_off0000da57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA57 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f269.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF269 18116 bytes
SHA-256: 86c96d611e30556a36cfbaf25f9b5bb28db6a36545563ebb41170a2e3b72657f
font_02_sfnt_off0001214d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1214D 11644 bytes
SHA-256: 273f3ec1164cb9804a45bb02767697739c5f5b369c56956ae56384f601870d92