Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5a9e7eb71cd9360…

MALICIOUS

PDF

68.6 KB Created: 2021-09-25 03:55:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f703b78a3b92df3e2c11f5cf41d4c9ee SHA-1: 8061f82d8289444d2b42e8b6aa4ca7a450d66531 SHA-256: c5a9e7eb71cd9360393dbabc50f5d8e132ec657ce664c00aea21f17a3b063723
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a phishing or malware distribution attempt. The ClamAV detection and ML classifier strongly suggest malicious intent, likely involving the execution of JavaScript to redirect the user to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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 link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://cructi.ru/uplcv?utm_term=business+english+writing+exercises+pdf
    • http://rintoyo.com/userfiles/file/minalirino.pdf
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/dc86a59bb3460938c6a314ece5e54d06/buponelexajexu.pdf
    • http://vetranhtuong.info/luutru/files/topen.pdf
    • http://recepti.plovdivweek.com/js/ckfinder/userfiles/files/1524932973.pdf
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/v5qkedi2enlgh222n5rauh9ron/xodefaxoxozigilovugug.pdf
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/ra5t1lpdqfmpbu8alv08fnbtar/91684484433.pdf
    • http://ark-mr.com/data/home/qxu2063190031/htdocs/uploadfile/files/gegitil.pdf
    • http://autowagon.it/userfiles/files/76281030632.pdf
    • https://sooryasales.com/uploads/file/didux.pdf
    • http://sb-78.ru/files/file/gelijeridutaxadumuk.pdf
    • http://daiwavn.com/uploads/image/files/jetafoze.pdf
    • https://maintogelonline2.org/contents/files/6703944348.pdf
    • http://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/34467795934.pdf
    • https://cs168.tw/upfiles/editor/files/fatimexipikafululo.pdf
    • http://combatkuntao.com/ckeditor/ckfinder/userfiles/files/51453656572.pdf
    • https://iieng.org/editor/ckfinder/userfiles/files/44810084363.pdf
    • http://3e3i.com/UserFiles/file///welitufiwo.pdf
    • http://ubestsports.com/imager/files/20210903144746.pdf
    • http://studiotecnicolari.it/userfiles/files/lazokosikukelenotumekeg.pdf
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161434ed90373f---77792025445.pdf
    • https://apatity.verlauf-ekb.ru/admin/ckfinder/userfiles/files/60673595600.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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ac14.bin
dfb5e46f62dc749dd005273769b8957b152b742b89c85e1d0c7fe1d8bdc81c4b
pdf-font-stream PDF embedded font (sfnt) at offset 0xAC14 15824 bytes
font_01_sfnt_off0000d404.bin
9189fb57e775b3d3ff1fed3614a20dda3dfe32017aeff92d723a407beff034b9
pdf-font-stream PDF embedded font (sfnt) at offset 0xD404 10956 bytes
font_02_sfnt_off0000ed3d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xED3D 16792 bytes