Malicious PDF — malware analysis report

Static analysis result for SHA-256 87751b35887c33f7…

MALICIOUS

PDF

79.9 KB Created: 2021-05-23 12:55:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: ea7380e00f2f48f8af16e5c090de393b SHA-1: 9b663e9f38954a58b0f29652cf7baeb1378d1289 SHA-256: 87751b35887c33f7e86e2425dcfbd878913e321206881b8ce1c39678504f06b1
254 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, identified as a link farm, with a critical heuristic firing for a malicious redirector. The primary redirector URL, 'https://crophysi.ru/strik?utm_term=iihf+world+juniors+2018+roster', is likely used to lead users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, consistent with phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9967

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
  • 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://crophysi.ru/strik?utm_term=iihf+world+juniors+2018+roster In PDF document text
    • https://cdn-cms.f-static.net/uploads/4453134/normal_6011365088a6d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4414342/normal_5fe0d1610b96d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369656/normal_60182fac1a250.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417992/normal_600a62154c788.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446166/normal_600e84104da25.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4471083/normal_6028696914c1b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460476/normal_606b92945597c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4444358/normal_601935f576eff.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403531/normal_6057b6afabcbb.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379842/normal_605c50255af9b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4422640/normal_601c65063a50b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480876/normal_605bc7fd7d3ce.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416792/normal_606e4a1639caf.pdfIn PDF document text
    • https://sibuzowad.weebly.com/uploads/1/3/2/8/132814892/472d755d22d0f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4390055/normal_605b879b75126.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4500432/normal_6068ec4e0f801.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4371246/normal_5fdc48c345216.pdfIn PDF document text
    • https://sajofagexureleb.weebly.com/uploads/1/3/4/6/134652103/giwilufapububak_gaxilonat_gaxigenevuwogi_mononolaw.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4403263/normal_5fcbeb4063874.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4491946/normal_604813226575c.pdfIn PDF document text
    • https://tazesarazuf.weebly.com/uploads/1/3/4/7/134726557/dulupabevaxepowuv.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/5fc51f2a-d6a3-4788-8896-088181d1891c/30867444668.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6130732f-8f15-496c-9822-7ca67b635bed/iron_man_2_movie_download_in_hindi_filmymeet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fa3c3c8d-963c-4633-a585-d4a3b05af204/68576164648.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/75b3abff-b715-444d-bca3-f7bb87a3680d/apush_review_packet_answers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/437dd395-6e5e-4b4c-ae0a-566962f671cc/15553912130.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_off0000fb57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB57 5412 bytes
SHA-256: 861bca41317783441f199d6cdbaa407b2374ec8fd89cfc417c45954efc0f7dd9
font_01_sfnt_off00010ddb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DDB 10584 bytes
SHA-256: 5b57d6e37e952d0b2b9f8d828c05009a9e16323ddc2bb69d6269cddd16a97c00