Malicious PDF — malware analysis report

Static analysis result for SHA-256 23a61f3d905466b1…

MALICIOUS

PDF

77.4 KB Created: 2021-09-21 20:37:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a3775d557eab65b8d276e93cc25f8604 SHA-1: 6852df2af3191b07c81ac9800ca74decd298a589 SHA-256: 23a61f3d905466b112348d84ad4e820fdd1ec5d8d43558c1a1200eee71205bd0
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external URIs, many of which point to disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. The embedded JavaScript is a common technique for executing malicious code or redirecting users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://synerhu.ru/uplcv?utm_term=online+crossy+roads PDF link annotation
    • http://lexus-custom.com/js/upload/files/23961190248.pdfIn PDF document text
    • https://radekslodkiewicz.pl/files/file/wowexovazonuximudav.pdfIn PDF document text
    • http://slovoveri.org/userfiles/wajovigilit.pdfIn PDF document text
    • http://cuacongtudongbinhduong.com/upload/files/naxulisuxumozene.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ed70345828---68187536532.pdfIn PDF document text
    • https://arbormaster.net/uploads/files/67142371451.pdfIn PDF document text
    • http://hurtglass.pl/upload/file/febegamivupebitolovajuku.pdfIn PDF document text
    • http://fine-trading-knotwork.com/uploads/media/72763474910.pdfIn PDF document text
    • http://hengtongrongshang.com/jingkelun/userfiles/files/20210913131611.pdfIn PDF document text
    • http://tcsklife.com/filespath/files/20210918150513.pdfIn PDF document text
    • https://shaplaconsulting.com/app/webroot/ckfinder/userfiles/files/jolujaderosozuz.pdfIn PDF document text
    • http://bidmitt.com/img/files/file/36138796021.pdfIn PDF document text
    • http://kammerchor-lindau.com/file/dolikekoz.pdfIn PDF document text
    • http://fcraregistration.com/UploadedData/file/88923854257.pdfIn PDF document text
    • http://connectcontrol.net/files/userfiles/files/93843175601.pdfIn PDF document text
    • http://akpanlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/bebodumavaw.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161494b737e65d---fuduvutoburovamaxupiv.pdfIn PDF document text
    • https://ekinyalitim.com/depo/sayfaresim/file/wokonijubarugasomivegem.pdfIn PDF document text
    • http://global-leasing-management.com/uf/file/murigikedazikexotow.pdfIn PDF document text
    • https://irisapp.cn/uploadfiles/fckeditor/20210910/file/16312374188332.pdfIn PDF document text
    • http://misterholidaysanprisco.it/userfiles/files/talinigidalogisawive.pdfIn PDF document text
    • https://geloracinta.com/contents/files/rekidumogobuzuvufel.pdfIn PDF document text
    • http://gpshardorawal.com/hemkunt/userfiles/file/jixagabijojufovulegubukig.pdfIn PDF document text
    • http://kripasec.com/userfiles/file/bazowa.pdfIn PDF document text
    • http://professionalcatererspaul.pageindia.com/resume/cms_files/files/juworezejatuxafesu.pdfIn PDF document text
    • http://webinaris.blog/ckfinder/userfiles/publics/files/7526422811.pdfIn PDF document text
    • 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_off0000ca28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA28 17656 bytes
SHA-256: 54c5c3674adf30fa3ac5488c947af22c54e3e81c6da645360f8b8dce8b72a876
font_01_sfnt_off0000f7dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7DC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010ff3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FF3 10404 bytes
SHA-256: 66ee996f9b6753b5d5cb8c77aff7d5ec7d9f263b39111dcac9b5e46d3fc1b17b