Malicious PDF — malware analysis report

Static analysis result for SHA-256 a880caa96a18c583…

MALICIOUS

PDF

66.8 KB Created: 2021-02-26 19:20:45 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: ec927cb0eed074c70d7a6601ca09f9c6 SHA-1: 40d779cbe9839145663063bac9c588628952e0b2 SHA-256: a880caa96a18c583b168576023035d7776a6be4688835c0de2fed86cfb75a351
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many of which point to SEO-optimized content farms and redirectors, a common tactic for phishing and malware distribution. The heuristic PDF_SEO_LINK_FARM and PDF_SEO_UTM_REDIRECTOR_LINK indicate a deliberate effort to create a link farm for malicious purposes. The presence of a malicious ML classification and ClamAV detection further supports its malicious nature, likely serving as a lure for a phishing attack or to download a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9578

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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://zajinet.ru/award?keyword=equivalencia+neumaticos+moto+pulgadas+a+milimetros PDF link annotation
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    • https://static.s123-cdn-static.com/uploads/4447641/normal_5fed6dffbf2b1.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417221/normal_5ff550ef6ac65.pdfIn PDF document text
    • https://mixunolonuwoja.weebly.com/uploads/1/3/0/9/130969204/37ef66868.pdfIn PDF document text
    • https://pinozawekik.weebly.com/uploads/1/3/4/5/134589254/4055126.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416934/normal_602cd8171a167.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4499329/normal_602c9e3c16973.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4468828/normal_602227942fe41.pdfIn PDF document text
    • https://bosamekuxukis.weebly.com/uploads/1/3/4/6/134672370/3473796.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417526/normal_5fe8483058ffe.pdfIn PDF document text
    • https://zovakobazala.weebly.com/uploads/1/3/1/4/131456363/sasijex.pdfIn PDF document text
    • https://s3.amazonaws.com/fovezewi/adding_fractions_with_different_denominators_worksheet.pdfIn PDF document text
    • https://s3.amazonaws.com/firigugixujotov/bebe_cool_ft_b2c.pdfIn PDF document text
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