Malicious PDF — malware analysis report

Static analysis result for SHA-256 51b4f6ac3a80b329…

MALICIOUS

PDF

81.9 KB Created: 2021-04-17 10:37:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ba407873b864757b783d31b1f431b216 SHA-1: ad051a54b0cf08500952d564830687ec44f8db90 SHA-256: 51b4f6ac3a80b329f3b4c86f67ea2048f9fc2001931c2ed6e9ccd70590d26dd1
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains a large number of external links, a technique often used for SEO poisoning or to direct users to phishing sites. One of the primary URLs identified is https://vilenefex.ru/strik, which is likely part of the malicious infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://vilenefex.ru/strik?utm_term=can+i+really+learn+spanish+with+rosetta+stone
    • https://susejovidexoxi.weebly.com/uploads/1/3/0/7/130775922/ridurow.pdf
    • https://cdn-cms.f-static.net/uploads/4465270/normal_6054e5d68218b.pdf
    • https://cdn-cms.f-static.net/uploads/4455180/normal_5fd17e56c0b07.pdf
    • https://rodazikajoreme.weebly.com/uploads/1/3/0/8/130874285/1378387.pdf
    • https://cdn-cms.f-static.net/uploads/4417658/normal_604e17b6ee5c3.pdf
    • https://static.s123-cdn-static.com/uploads/4451929/normal_6004b73cec12e.pdf
    • https://netopanuneju.weebly.com/uploads/1/3/4/4/134493403/gipuwamusaj.pdf
    • https://kewojuposadut.weebly.com/uploads/1/3/4/3/134374438/vutozapudemupujuzu.pdf
    • https://static.s123-cdn-static.com/uploads/4456686/normal_5ff8bad5ac1f5.pdf
    • https://kobuzefejara.weebly.com/uploads/1/3/1/4/131437799/337f6f2ce8.pdf
    • https://cdn-cms.f-static.net/uploads/4479688/normal_6045ff21e17e1.pdf
    • https://lukuxafibufogi.weebly.com/uploads/1/3/5/4/135400428/434134.pdf
    • https://cdn-cms.f-static.net/uploads/4406793/normal_5fe9ffb9e3b77.pdf
    • https://mixadawobavaw.weebly.com/uploads/1/3/5/9/135982386/wunopitoxuvasilad.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/kosipefojaw/6183970861.pdf
    • https://s3.amazonaws.com/pusolefosex/mepinulepewexonobe.pdf
    • https://uploads.strikinglycdn.com/files/5d6e5feb-dcde-4e40-9c93-601a8aa302d2/reset_brother_hl2170w.pdf
    • https://s3.amazonaws.com/marimejerebo/hp_6940_printer_ink_light_flashing.pdf
    • https://uploads.strikinglycdn.com/files/1eb7d227-8dc4-4992-a182-e3ee39e85ce7/weight_loss_exercise_plan_at_home_printable.pdf
    • https://uploads.strikinglycdn.com/files/8c26037c-6b2a-47ae-b87d-d81c57302822/vobegamed.pdf
    • https://uploads.strikinglycdn.com/files/c5df392b-73d9-4729-b323-af4b15e7aae9/rurakelitadonemoxav.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010078.bin
ada23f848da6a4bb9579af4292cb108cc7ea239435aba67986921ff23f1f1892		 pdf-font-stream PDF embedded font (sfnt) at offset 0x10078 5004 bytes
font_01_sfnt_off00011188.bin
8b5effeaf4125e10830f131d6c0ca6a9512dd72301d74af237cdf9239152d3e0		 pdf-font-stream PDF embedded font (sfnt) at offset 0x11188 11788 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.