Malicious PDF — malware analysis report

Static analysis result for SHA-256 8533a5255daae702…

MALICIOUS

PDF

79.5 KB Created: 2021-06-24 13:55:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 1c85b48caa0804cc2b24eb33c4f279bd SHA-1: b7cc66670d6e5cd8505702abf0f92427612a89a7 SHA-256: 8533a5255daae702944d6a63b1406e9b4e149a1316d30c264df193cd017a7ff5
164 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript, suggesting it may attempt to execute malicious code or redirect the user to phishing sites. The numerous external URIs pointing to compromised CMS upload storage and disposable hosting further support a phishing or malware distribution scheme.

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 https://huntic.ru/uplcv?utm_term=pdfwriter+class+in+c%2523 PDF link annotation
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160b380acd8890---gitabekokudegomazowi.pdfIn PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607ce837d5369---24790046068.pdfIn PDF document text
    • https://audreyheselmans.com/_files/file/kaziworalosilajisoju.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/13c02fc8618fb955e6e02f504e255e87/dogomiwinowusepitexig.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/160a5299fd85be---wafoxolisapomixuzupiv.pdfIn PDF document text
    • http://xboxheerlen.nl/userfiles/file/55471299946.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609a0e99539cd---13862557998.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160926bb767793---kovep.pdfIn PDF document text
    • http://studiotecnicoprato.eu/userfiles/files/vafage.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090f01c223c8---335809899.pdfIn PDF document text
    • http://visit-pune.com/userfiles/file/vokusogugopave.pdfIn PDF document text
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/lur8b69r5iuda81s1banjdbks1/52623103488.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609caf29babb2---mopeden.pdfIn PDF document text
    • https://www.wikiwebagency.it/wp-content/plugins/super-forms/uploads/php/files/2d4599aea8a247b131fe30a419ab47d2/jedeborazovorudujelu.pdfIn PDF document text
    • https://ev-owners.jp/userfiles//files/nexunu.pdfIn PDF document text
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160b564679e38b---virabarobudekotujoretil.pdfIn PDF document text
    • http://skyrunarser.com/js/fckeditor/editor/filemanager/connectors/php/connector.php/upfiles/file/210609124236216480w7ukw4.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_off0000f671.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF671 5108 bytes
SHA-256: 10f8fecb821cfe78d556e20e65e62ea8cae0d99ac4814468c0b038194a1624d2
font_01_sfnt_off000107f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107F7 11756 bytes
SHA-256: 3ec6ef7f831b046c2c3dd3975bad88a3597a36e6c60adec846123dba2506c8dd