Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a99528d5c8fd569…

MALICIOUS

PDF

78.2 KB Created: 2021-06-10 15:17:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 43bb19aa45a36e538eccfdad39626fbe SHA-1: cd179550e90482c5a31f0876120c3f1fd2c81f6c SHA-256: 4a99528d5c8fd569a89103b81813f107dc0a7c33a41379d2e82247ab1a8acb6c
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress upload directories, suggesting a phishing or redirection scheme. The presence of a UTM term in one URL further supports a campaign-driven approach.

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://pixomot.ru/uplcv?utm_term=ian+mckellen+as+macbeth PDF link annotation
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088cfd7b2bff---38088396704.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608754d968736---96370669370.pdfIn PDF document text
    • http://airconbank.com/upload/fckeditor/file/sovugejipogeli.pdfIn PDF document text
    • http://vienkiemis.lt/app/webroot/uploads/userfiles/files/bawedavajudekesizim.pdfIn PDF document text
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/723092e244ed9c8b83f304d13e19aaa0/28518229688.pdfIn PDF document text
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160865b1ac5ce8---78601478855.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160720ae908b37---21479415855.pdfIn PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/1606ffde256fb9---xibulaxubage.pdfIn PDF document text
    • https://mymango.ru/wp-content/plugins/super-forms/uploads/php/files/5cfbd60f4999a4e04acd72a0205e4354/xeputiziwoborizi.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/og012bokkj0eh13r0i4dkgesjg/30012488242.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/160820e44593e0---85891165726.pdfIn PDF document text
    • https://lightsourceindiana.com/wp-content/plugins/super-forms/uploads/php/files/d2946a93a6c6c118195b23a9d183a55b/42702053318.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/f10ab38612723286f0bb76770e604259/93535209200.pdfIn PDF document text
    • http://buffagiuseppeinfissi.com/userfiles/files/71848048251.pdfIn PDF document text
    • https://aartipalette.com/userfiles/file/puvipetijek.pdfIn PDF document text
    • http://softwarefactory.nl/images/file/remowafebekixutumenijosas.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/ef4c9fc556d07be0e1f17edbeadfd4b2/zegakexofunuzew.pdfIn PDF document text
    • https://gfow.om/wp-content/plugins/super-forms/uploads/php/files/efrhghekado0cr4rnjp246fa69/rikitipuxava.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1609b8cd993e95---32804657321.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f454.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF454 5084 bytes
SHA-256: 63b0b4cb5b91683837a3624cea6953753a9656c19c4314f2444f4f8e20bc1b5b
font_01_sfnt_off0001057f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1057F 11504 bytes
SHA-256: cd2d95775898b8c41d27b636013e5a9a4ceaa6d8af3ee39de1a84ff254947e4c