Malicious PDF — malware analysis report

Static analysis result for SHA-256 c937b14b0b246d43…

MALICIOUS

PDF

81.3 KB Created: 2021-09-21 08:22:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1135273dac2cc2a9540c5571645b1d0c SHA-1: 9a6eb6d4317bb96d5e511cc63b11dbfb4f284375 SHA-256: c937b14b0b246d43ad2df8af3cbdc4ca9f0675e5fd52bd651de59d4501c6537a
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code within documents. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document is designed to host numerous links on disposable domains, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or delivering a secondary payload via the embedded JavaScript.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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://tamtam.com.ua/wp-content/plugins/super-forms/uploads/php/files/b5b8d4b9b2f324ef99f0c841f7fc5377/tebup.pdf In PDF document text
    • http://sjar-tech.com/uploadfile/file///2021090814052271.pdfIn PDF document text
    • https://fundreamz.com/ckfinder/userfiles/files/mozumusidosizirajapabi.pdfIn PDF document text
    • http://togclick.com/media/userFckfiles/file/94154498867.pdfIn PDF document text
    • https://jaukiaplinka.lt/ckfinder/userfiles/files/jetamexegamebibovebid.pdfIn PDF document text
    • http://aodaibooking.com/FileData/ckfinder/files/20210914_C7861AE5FD5BDB4B.pdfIn PDF document text
    • http://kurskodkb.ru/page_edit/_samples/userfiles/files/80200108870.pdfIn PDF document text
    • https://rocksoliddesigns.biz/userfiles/file/55326653588.pdfIn PDF document text
    • http://bdpq.hungminhits.com/files/uploaded/files/88050839089.pdfIn PDF document text
    • http://nikkenj.com/userfiles/file/52376645547.pdfIn PDF document text
    • http://form4concrete.ru/pics/cont/file/20853194805.pdfIn PDF document text
    • https://finliz.lt/i/File/zazukokijakovosuxisujodab.pdfIn PDF document text
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab04613b45---64417159501.pdfIn PDF document text
    • http://cuathepvangohaiduong.com/images/ckeditor/files/42787570893.pdfIn PDF document text
    • http://naturallabs.de/userfiles/file/85050900201.pdfIn PDF document text
    • http://alburigiott.it/userfiles/files/2708464049.pdfIn PDF document text
    • https://csodamalom.hu/files/files/33233036372.pdfIn PDF document text
    • http://satcomlink.com/userData/board/file/60238325114.pdfIn PDF document text
    • http://strandedtattoo.net/file/8145165116.pdfIn PDF document text
    • http://ebonit.light.bg/includes/libs/ckfinder/userfiles/files/54234964705.pdfIn PDF document text
    • http://www.stemcellhairclinic.com/files/files/48782907778.pdfIn PDF document text
    • https://piphoto.tw/uploads/files/202109080518592207.pdfIn PDF document text
    • http://www.ville-civaux.fr/admin/js/ckfinder/userfiles/files/91471268288.pdfIn PDF document text
    • http://hmconcretemixingplant.ru/d/files/begizuf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=book+week+competition+ideasPDF 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_off0000d8d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8D4 17512 bytes
SHA-256: 311c6b4d22cae05e4a66fc5bea8d8a916228a9ae7cf5af09db52153bf8b904d9
font_01_sfnt_off0001066b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1066B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E82 10760 bytes
SHA-256: 44fd7dbdf8de9475191a89aa3a3ef5a2dbcb9de0ccc3cc802a7c8009ecf7ddcb