Malicious PDF — malware analysis report

Static analysis result for SHA-256 acf78eb81cd8df46…

MALICIOUS

PDF

72.7 KB Created: 2021-02-17 08:34:16 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-18
MD5: 5a0a2c31d310970a365863696870c221 SHA-1: cd22ee03be5e215656a0e1d2d5c2b536c595e077 SHA-256: acf78eb81cd8df465827abe20ea41648b20f4aa6bc05c073cecd99cc33b59cd8
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

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
  • 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.
  • 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://jacksth.ru/123?utm_term=how+often+should+you+do+the+5+tibetan+rites PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4390638/normal_5ff9039e8b892.pdfIn PDF document text
    • https://webegerux.weebly.com/uploads/1/3/4/7/134759049/ripenemin.pdfIn PDF document text
    • https://cdn.sqhk.co/perolurowona/gcmXLXk/felunivizotiraviwik.pdfIn PDF document text
    • https://gewipilozu.weebly.com/uploads/1/3/0/7/130775211/b6e971de3e24c26.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4423136/normal_5fd92e1bf32a8.pdfIn PDF document text
    • https://ratofesut.weebly.com/uploads/1/3/5/3/135304008/zirixipekebu_bujet.pdfIn PDF document text
    • https://cdn.sqhk.co/lejesapazud/Lgfhajc/metal_pay_news.pdfIn PDF document text
    • https://xavuzilutose.weebly.com/uploads/1/3/1/0/131070872/kasad-vipuwo-betafus-visozegizu.pdfIn PDF document text
    • https://tenadugal.weebly.com/uploads/1/3/2/7/132740541/248677.pdfIn PDF document text
    • https://cdn.sqhk.co/tidelefuzin/Pbjgtjd/word_jumble_maker.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4472475/normal_5fddcdba6d242.pdfIn PDF document text
    • https://govewusig.weebly.com/uploads/1/3/0/9/130969429/8d9062fa826.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4473616/normal_601d2afd0e7db.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_off0000dedb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEDB 5412 bytes
SHA-256: 18fe6421e1a7e96790982c567d19d67fdf79c5ffa34d92cd2adc722ba8db3cc9
font_01_sfnt_off0000f15a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF15A 10116 bytes
SHA-256: d51530d5488412a030ce1ed7b909fba0a837a096c82364fb121f92116fc82c53