Malicious PDF — malware analysis report

Static analysis result for SHA-256 c713bae0eccaf465…

MALICIOUS

PDF

77.2 KB Created: 2021-04-17 00:14:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 10fc456af8849147b4e1a283e12ca9d7 SHA-1: c671b3964ff981b56d5eea5a79a1c124c1931546 SHA-256: c713bae0eccaf465c8238af9031d30735a081860904c86b82ea59995344b9abe
196 Risk Score

Malware Insights

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

The PDF file contains numerous external links, with a critical heuristic identifying it as an SEO link farm and a high-severity heuristic flagging an image lure linking to an SEO redirector. The primary malicious URL identified is https://maypoin.ru/strik?utm_term=mcat+physics+equations+cheat+sheet, which is likely used for phishing or to serve a second-stage payload. ClamAV also detected this file as Pdf.Phishing.Trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://maypoin.ru/strik?utm_term=mcat+physics+equations+cheat+sheet PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4394079/normal_6052e07bf1c05.pdfIn PDF document text
    • https://cdn.sqhk.co/kapudome/Dhjihgj/collaborative_learning_strategies.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4414689/normal_5ff036039e59c.pdfIn PDF document text
    • https://tagasudinabasow.weebly.com/uploads/1/3/5/3/135325797/9effce4d529.pdfIn PDF document text
    • https://cdn.sqhk.co/mapetidul/ghcIvii/rasigub.pdfIn PDF document text
    • https://cdn.sqhk.co/xarozowuzosa/jdZB1hg/kobezupabul.pdfIn PDF document text
    • https://cdn.sqhk.co/baxemazisod/dfjgcie/sanoluzatun.pdfIn PDF document text
    • https://pimanubidaw.weebly.com/uploads/1/3/4/3/134353005/posesewila-biror.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4412584/normal_605939740db92.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4474727/normal_6050715e55628.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4472788/normal_60198751bad58.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409000/normal_602442de9db13.pdfIn PDF document text
    • https://cdn.sqhk.co/pixazizaze/AKibhcI/vesezozi.pdfIn PDF document text
    • https://jisixeda.weebly.com/uploads/1/3/1/4/131409884/ff9886.pdfIn PDF document text
    • https://vusowixaxepuw.weebly.com/uploads/1/3/1/3/131381533/ropila.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421040/normal_60229af8da083.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4477913/normal_5fd21d5967a52.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/fidobakipivogit/how_many_chapters_are_in_harry_potter_book_6.pdfIn PDF document text
    • https://s3.amazonaws.com/gadumagabusodel/13959107085.pdfIn PDF document text
    • https://s3.amazonaws.com/nijudow/lonely_planet_guide_berlin.pdfIn PDF document text
    • https://s3.amazonaws.com/midaguvimabof/mawerurebizokaxeve.pdfIn PDF document text
    • https://s3.amazonaws.com/dukexajuj/tinemobu.pdfIn PDF document text
    • https://s3.amazonaws.com/xixonu/63324758823.pdfIn 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_off0000eacc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEACC 5124 bytes
SHA-256: 2f495461b65846bac829a7854a2ca1cd8482a9eef18a48cdd1786ce60141d5ab
font_01_sfnt_off0000fc54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC54 12268 bytes
SHA-256: ce277e1fb90245ae427baa6a6e713b296838e424d56751b3e2039befe22957d9