Malicious PDF — malware analysis report

Static analysis result for SHA-256 4129aa51f412e44b…

MALICIOUS

PDF

71.7 KB Created: 2021-06-16 09:05:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 405752a0d0e2586d88c92efd189319aa SHA-1: 3500e934b14c31a7891cf8259664efa44a95bfef SHA-256: 4129aa51f412e44b7b7174d3738d524fb9b1f0ea1de9216fb60ef019403b51c0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous links to external websites, many of which are hosted on compromised WordPress sites, suggesting a link farm or phishing lure. The document body, though heavily obfuscated, appears to reference 'Canterbury tales vocabulary worksheet answers', indicating a social engineering pretext to drive users to malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://cructi.ru/uplcv?utm_term=canterbury+tales+vocabulary+worksheet+answers PDF link annotation
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1607c4786d3476---24574408374.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160842fb340187---28617422203.pdfIn PDF document text
    • http://shmountaineering.co.uk/wp-content/plugins/super-forms/uploads/php/files/f0gfcclcjastr65keqg301kfm3/81987723080.pdfIn PDF document text
    • http://tavernadelsnoguers.com/wp-content/plugins/super-forms/uploads/php/files/2c1b65ac0d523eddfcce63c0e9f6a715/89714466641.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/90588029850.pdfIn PDF document text
    • http://imaginove.eu/data/Files/wetaxajidewuxa.pdfIn PDF document text
    • http://geometrabottero.it/userfiles/files/20990925152.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077d76eab230---zukudezulolitegoxotuwib.pdfIn PDF document text
    • https://minutesnap.com/wp-content/plugins/super-forms/uploads/php/files/709c3df841dae33525de236f64d696cc/75714017338.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160c334792bf3d---52383802316.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/1609b721594c16---kamuzopoz.pdfIn PDF document text
    • https://cottonweb.net/userfiles/file/natajilujonilak.pdfIn PDF document text
    • http://amdind.com/userfiles/file/17358220372.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/1608f72900ff95---tibaxeda.pdfIn PDF document text
    • https://www.sadcmedia.com/wp-content/plugins/super-forms/uploads/php/files/cka4408mguc32pi42skdirqlh1/sitidoputigarijamawisu.pdfIn PDF document text
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/ef58g6voe1ft9aok0i25i1phm0/74042861421.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ce4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE4E 5200 bytes
SHA-256: f9cb50dcafe22d5621c53a83214288e8bf04c10da167ec65210e977a5e5b80b5
font_01_sfnt_off0000e016.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE016 10256 bytes
SHA-256: 9659a6b8f3f8c063a7f3a04a52a2906a3c72608ab6b1db2312edaeb40962b5ed
font_02_sfnt_off0001033b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1033B 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176