Malicious PDF — malware analysis report

Static analysis result for SHA-256 90133ca756859e6a…

MALICIOUS

PDF

73.1 KB Created: 2021-03-10 16:20:36 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 149607eab3146dbfd7ab3b824eace1ff SHA-1: bb546783a6e4f2ea2940c84b37e98578bfd194ad SHA-256: 90133ca756859e6add618675ef9f9c3673c546359f05ad8bae2649fa79130440
196 Risk Score

Malware Insights

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

This PDF file exhibits characteristics of a phishing lure, specifically designed to trick users into clicking on links that lead to further downloads. The heuristic 'PDF_SEO_LINK_FARM' and 'PDF_SEO_UTM_REDIRECTOR_LINK' indicate a mass of external links, with one prominent redirector URL pointing to a site offering 'niccolo machiavelli books free'. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • 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
  • 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://xajibur.ru/123?utm_term=niccolo+machiavelli+books+free PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4454286/normal_6007eb425b00b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367311/normal_601185b29d6b9.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4475383/normal_5ffb0837dc508.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4385850/normal_6012255f6b6b1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393204/normal_603c5444dc32d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4452206/normal_602857d8722b5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4486971/normal_6040b94d23cb8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421944/normal_6029e9189d30c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369651/normal_5feaf05abe3b7.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/xiwevitox/blister_in_the_sun_guitar_tab.pdfIn PDF document text
    • https://b3079848-b07e-4d89-9244-05dfa5dd91fe.filesusr.com/ugd/3ab5ed_fb386f52161742c1b807bdf923111041.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/jukoxisojow/avatar_movie_in_tamil_language.pdfIn PDF document text
    • https://s3.amazonaws.com/novifamigot/honeywell_chronotherm_iii_reset.pdfIn PDF document text
    • https://s3.amazonaws.com/fulazelof/sadavexanegefatefomo.pdfIn PDF document text
    • https://s3.amazonaws.com/roxawo/50963413258.pdfIn PDF document text
    • https://s3.amazonaws.com/zidosozawok/consultant_agreement_template.pdfIn PDF document text
    • https://s3.amazonaws.com/kifutizijebuj/jebalogukuwuruj.pdfIn PDF document text
    • https://s3.amazonaws.com/gedimuta/65326701145.pdfIn PDF document text
    • https://87da31d5-d184-45e7-a456-0ad082c8bd65.filesusr.com/ugd/55e94a_8c03acab742645da91da60682dae0978.pdf?index=trueIn PDF document text
    • https://1c8fadd7-09eb-4d2b-9d42-8e747ba5ce52.filesusr.com/ugd/60625b_5211055d2f1445d1a2a7a6eef8516e35.pdf?index=trueIn PDF document text
    • https://8d90b851-447f-4cfc-ac95-1e867b71b983.filesusr.com/ugd/b371d9_ea23048dd3224bc4a84a41dca06284eb.pdf?index=trueIn 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_off0000df9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF9D 5352 bytes
SHA-256: 272fb777ae6f38d6bc80f149ea99cd342371dd94a274258f7349721b34231257
font_01_sfnt_off0000f1b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1B7 10960 bytes
SHA-256: 32d66fe704f98ed3d123dcdb54d997d8edcc31286f6937e7b2d2634e31fe5845