Malicious PDF — malware analysis report

Static analysis result for SHA-256 81b1c836e10adf0b…

MALICIOUS

PDF

38.9 KB Created: 2020-10-31 12:52:59 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: 28efe066c97caf3e8260a7f6258b1d93 SHA-1: 93d294fa329d3dca6a7f3fd91051e5d738a49505 SHA-256: 81b1c836e10adf0b6c9598bf842ab7dda5791517c50240bf90b927a83f228483
194 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

This PDF file contains numerous embedded links designed to redirect users to malicious infrastructure, specifically identified as a redirector at 'https://cctraff.ru/aws?keyword=garry+kasparov+masterclass+free+reddit'. The document body and heuristics indicate a lure related to a 'Garry Kasparov masterclass', likely a phishing or scam attempt to exploit user interest. The ML classifier strongly flagged this PDF as malicious, and the presence of a link farm suggests an attempt to manipulate search engine results or distribute malware.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://cctraff.ru/aws?keyword=garry+kasparov+masterclass+free+reddit In PDF document text
    • https://cdn-cms.f-static.net/uploads/4414501/normal_5f9825d476947.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4394062/normal_5f99b7e120b88.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382186/normal_5f95f244947a2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369486/normal_5f96fa1a8b4c8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375891/normal_5f8acad142edb.pdfIn PDF document text
    • https://texitanoz.weebly.com/uploads/1/3/0/7/130739996/zananadag_momazeji_zosud_raxejagemedi.pdfIn PDF document text
    • https://xexegetogud.weebly.com/uploads/1/3/4/3/134375989/wepibexub.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415308/normal_5f9800e35c22d.pdfIn PDF document text
    • https://duxataravur.weebly.com/uploads/1/3/4/0/134017775/3786895.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366313/normal_5f98330d2ae41.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383930/normal_5f9214ba3f90e.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/sepawi/pdf_split_merge_download.pdfIn PDF document text
    • https://s3.amazonaws.com/henghuili-files/merriam_webster_dictionary_free_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5f38c914-ae20-4fc1-a4e1-6e978a162e11/weginuniwetumarati.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

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000583e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x583E 5560 bytes
SHA-256: aee967271354eb904966651e2e25e5a2cf7f66479bbbc2317c7c37d9bc37f740
font_01_sfnt_off00006b30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6B30 10448 bytes
SHA-256: b384ae52f8d6dc33c326008d3001b3e80e58f72d76bf7b53ecfb01f2f0127fb4

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