Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfb243dd3ed581b3…

MALICIOUS

PDF

76.0 KB Created: 2021-06-23 17:53:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-31
MD5: c4008d3e29b679b733f5e2da0382c4d0 SHA-1: 6274d7d88514bc00eb3418214b86fb4fe8147707 SHA-256: cfb243dd3ed581b3a33bac967a2e8d14e5feeda33d9a036fcb263481c6ff711b
164 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and a significant number of external URIs, many of which point to compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. The embedded JavaScript is a common technique for initiating malicious actions within PDF documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://rusiuojigalvoji.lt/wp-content/plugins/formcraft/file-upload/server/content/files/160ba2c1b5bf93---94501173749.pdf In PDF document text
    • https://rajaketiga.com/contents//files/65406324897.pdfIn PDF document text
    • http://1137.jp/app/webroot/js/ckfinder/userfiles/files/17431231442.pdfIn PDF document text
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b738ec4be5b---miridigogaxagozeletobegij.pdfIn PDF document text
    • https://nailseasupportgroup.com/wp-content/plugins/super-forms/uploads/php/files/d316af666b4f13ebc25a571270fff057/felino.pdfIn PDF document text
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/8a5d4b2eb5e19bceb773d9873d6b15b8/40960878868.pdfIn PDF document text
    • https://songhong.info/userfiles/file/46467742328.pdfIn PDF document text
    • http://assushop.com/userfiles/assushop.com/file/92198573701.pdfIn PDF document text
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/1608beb92d2b4b---nutinanisopo.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160cb559c8aa4e---67652382409.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160863384eacd0---wovadagi.pdfIn PDF document text
    • http://allmedicus.com/userfiles/file/minugigozujezuxele.pdfIn PDF document text
    • http://jamessham.com/admin/usercontent/file/56081237738.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/c8ed020065b2efaf22905f884123ba5f/balepenoledivi.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607cf425945e2---robikofovimadipejolona.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=henderson%2527s+equation+for+basic+buffer+solution+isPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eb40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB40 5276 bytes
SHA-256: 7d73d2584f414fae8d18edacedf5b1c4547ccb502b77ccb60c7d8525368ee301
font_01_sfnt_off0000fd3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD3F 11104 bytes
SHA-256: d57a23731bce8dec3361c8186f513ba87bc987b5f25cf4937c85fe6c63b6656f