Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f960a85998a48f4…

MALICIOUS

PDF

77.9 KB Created: 2021-09-11 00:57:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 7b3b092b917e57719c8b57ab7974a792 SHA-1: 63add036bda91ada42d3061698e3e658f9d4401c SHA-256: 5f960a85998a48f478420b1f89f8e2c670e5e9b4118b96149be3ce203ffc046e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many hosted on compromised CMS platforms or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and link farm heuristic point towards an attempt to leverage embedded JavaScript or other document features to facilitate these redirects.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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://www.hsbofmn.com/ckfinder/userfiles/files/lozemalo.pdf In PDF document text
    • http://brilspa.ro/userfiles/file///15009272549.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/bdac4580639eb76c3ff8f52bada7dd98/rumopababifoxekirawosuzoj.pdfIn PDF document text
    • http://apex-architect.ru/images/file/66868755247.pdfIn PDF document text
    • https://hydratrend.com/application/third_party/ckfinder/userfiles/files/telotumazuwimi.pdfIn PDF document text
    • https://protradingindia.net/userfiles/file/bajimulovepatidejutiveke.pdfIn PDF document text
    • http://www.ondebiz.com/userfiles/file/95066322847.pdfIn PDF document text
    • http://shinhwajudan.com/userData/board/file/volaloziziwiw.pdfIn PDF document text
    • http://gu-bo.cn/uploads/files/metiledasivazumum.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/161354fe2e375a---puritoredu.pdfIn PDF document text
    • http://www.accl-calibration.com/login/ckfinder/userfiles/files/fesejew.pdfIn PDF document text
    • https://cosmopolitanhotel.lastrada.bg/uploads/wysiwyg/files/wubuti.pdfIn PDF document text
    • https://dnmpaint.com/sdcc/images/file/35875820527.pdfIn PDF document text
    • https://ascend.sut.ac.th/ce/2017/src/plugins/ckfinder/userfiles/files/pajutidep.pdfIn PDF document text
    • http://kag.fr/userfiles/file/91866671677.pdfIn PDF document text
    • https://volnynaklad.cz/data/file/9415065843.pdfIn PDF document text
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161324637221df---96453911688.pdfIn PDF document text
    • https://iasvn.org/Images_upload/files/fetejik.pdfIn PDF document text
    • http://stellarp.com/userfiles/file/66560546426.pdfIn PDF document text
    • https://cribpointonline.org/cribpointonline/userimages/file/26368086361.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1613a674a28c3a---19922819637.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=distributive+property+with+exponentsPDF 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_off0000ca64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA64 17592 bytes
SHA-256: 64dbe5ee80ba36767720819c58bc516e63b6b941507dec253623b6350fd9de2f
font_01_sfnt_off0000f794.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF794 10752 bytes
SHA-256: 8f518956e41d72b315ebe4b5101594f3431a8ceee13069bf84fe6d71c3e53692
font_02_sfnt_off00011032.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11032 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1