Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fe1e193d5b5c924…

MALICIOUS

PDF

80.5 KB Created: 2021-09-10 12:27:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b2a8d1c5ea48e271d7835647c5ccb1df SHA-1: 757ae86fd5b5918bc3a5ca40223e577d3c2f4550 SHA-256: 4fe1e193d5b5c924d227a26e05b4115b7cc2e7b910647510eea24633bba7ab21
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories, suggesting a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the nature of the URLs and the PDF structure align with techniques used to deliver secondary payloads or redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 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.
  • 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://huntic.ru/uplcv?utm_term=worksheets+grammar+pdf+answers
    • http://uts.edu.co/portal/app/ckfinder/userfiles/files/25334372751.pdf
    • http://80tner.netsociality.com/upload/files/31963540752.pdf
    • https://nilsahost.com/calisma2/files/uploads/vilidusoratovukegex.pdf
    • http://telegid.tv/userfiles/files/memunerikixu.pdf
    • https://consurs.ro/ckfinder/userfiles/files/49250126165.pdf
    • http://mayinluatudong.com/uploads/userfiles/file/rulol.pdf
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b119e58d40---tuxanimukexigarapapi.pdf
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/03aedfd750389f17ba7d095483bddd8d/fapomuxewonujuwuzok.pdf
    • https://commonwealthsportsawards.com/userfiles/file/86994926114.pdf
    • https://fototipia.hu/files/files/nufamuwowebugexusus.pdf
    • http://obkladlazby.cz/userfiles/file/71828023431.pdf
    • http://topenglish.sk/app/webroot/gallery/files/56605746511.pdf
    • http://shijijiaming.cn/filespath/files/20210910095736.pdf
    • http://kusistoconstruction.com/userfiles/file/37406622422.pdf
    • https://ibextrail.com/editor-images/14148181615.pdf
    • https://egyediajandekotletek.hu/mvc/userfiles/file/gadikazukese.pdf
    • http://dakdekkersindex.nl/images/uploads/1141818271.pdf
    • https://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/e03dda28ab8efd4e1d563b7e11bf2a93/63592592208.pdf
    • https://wsbtitan.com/images/file/69521650398.pdf
    • https://haltia.mx/sii/ckfinder/userfiles/files/ruduzapunojo.pdf
    • https://www.willmarshelter.com/ckfinder/userfiles/files/jakagewuruvi.pdf
    • http://fred-robin.com/ckfinder/userfiles/files/vamej.pdf
    • https://bunianco.com/other_files/File/31385796756.pdf
    • https://ginniglobal.com/uploads/file/xilirudatoxuxeponevodelu.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_off0000d546.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD546 16792 bytes
font_01_sfnt_off0000ed5d.bin
6355e76c886b3dc7cfdfca97cedade7a1c74f86b537e67e1844b2e9daff0de7b
pdf-font-stream PDF embedded font (sfnt) at offset 0xED5D 10980 bytes
font_02_sfnt_off0001068f.bin
acbd9a4c1e170627ba6d5d9bc1d48f033bff2e30f9293d6a7dcb562c35a55499
pdf-font-stream PDF embedded font (sfnt) at offset 0x1068F 17660 bytes