Malicious PDF — malware analysis report

Static analysis result for SHA-256 d76bfe9d90c66159…

MALICIOUS

PDF

253.7 KB Created: 2021-08-15 16:23:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 5dc4d9669fccb99c664414e529e0df3d SHA-1: 9fdc420b25fa3a2976f01a928ecf5d78ec791dcb SHA-256: d76bfe9d90c6615972028385428e7a3de35277285db991d5a9bfb73250bcfab4
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains embedded JavaScript, indicating potential for malicious scripting execution. The PDF also features a link farm pointing to compromised WordPress upload storage, suggesting a phishing or credential harvesting attempt. The presence of embedded JavaScript and the nature of the URLs strongly suggest an attempt to download and execute further malicious content or redirect users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8721

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.
  • 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 http://ecohost.ru/pics/images/file/vigusetobi.pdf In PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fa8b3c84846---wixodepapefugirezo.pdfIn PDF document text
    • https://magnettoptan.com/upload/ckfinder/files/41056928638.pdfIn PDF document text
    • https://nothingbutsafetyglasses.com/userfiles/file/mopuvujalulopawelotetu.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608ba4b201b66---30841481621.pdfIn PDF document text
    • http://cc-loges.com/uploads/file/30549390685.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095d7d058a72---92459134933.pdfIn PDF document text
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/a831e2c7bec173be71f13871ab6bb4b5/mimukub.pdfIn PDF document text
    • http://saikunghouse.hk/userfiles/lefojiwemuzekesolin.pdfIn PDF document text
    • https://leavereview.com/customerinterview/ckfinder/userfiles/files/zavadopefazunebad.pdfIn PDF document text
    • http://smeclassof1987reunion.com/clients/37165/File/bigujukomuluno.pdfIn PDF document text
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160850e6ed6b72---23403097741.pdfIn PDF document text
    • http://esteticka-stomatologie.cz/files/content/file/10730455240.pdfIn PDF document text
    • https://www.mftelhas.com.br/adm/Editor/ckfinder/userfiles/files/petasojipunaw.pdfIn PDF document text
    • http://chinhlytailieuluutru.com/media/ftp/file/58246123014.pdfIn PDF document text
    • http://studioagronomoserragiotto.eu/userfiles/files/jevakafebobedulixanol.pdfIn PDF document text
    • https://fiscalonline.eu/app/webroot/files/userfiles/files/tazegako.pdfIn PDF document text
    • http://kencert.vn/uploads/image/files/fetutozefox.pdfIn PDF document text
    • http://esejsc.com/upload/files/73007330878.pdfIn PDF document text
    • https://golf-tout-terrain.com/publish/page/file/37088390155.pdfIn PDF document text
    • http://stalmont.eu/userfiles/file/gopafuvexawubenam.pdfIn PDF document text
    • http://codefon.hu/js/ckfinder/userfiles/files/jepasudug.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=alma+de+cristo+acordes+en+re+mayorPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0003862e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x3862E 19220 bytes
SHA-256: d7dba523bed3e69221a6fe180a4cf5bcbc7c36591d86f79e4a449a6c83f711f0
font_01_sfnt_off0003b718.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x3B718 10628 bytes
SHA-256: 950a7f72b8b5ac116fb2ffc2abb3d016c784f5db9efb81bf1591efdb6cfe119c
font_02_sfnt_off0003cf61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x3CF61 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1