Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca614204e2bc5e11…

MALICIOUS

PDF

68.8 KB Created: 2021-09-27 18:52:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: acd791f275a8724c776222eede06c121 SHA-1: eb4d0df8030028bc220d07e60842bacfc86d7955 SHA-256: ca614204e2bc5e11a4be5e2e852c93dc59f188ede795178f7c5cca509e03f958
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which point to external sites hosting PDF files, suggesting a link farm or redirection mechanism. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to obscure the true destination or distribute content through numerous small, disposable links. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's designed to lead users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 5

  • 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.
  • 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://siltri.com/fck_upload/file/mevafij.pdf In PDF document text
    • https://liur-krd.ru/userfiles/file/26454083384.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/4b118af82da781a43e1979a478469704/kabezarojiwumelojevola.pdfIn PDF document text
    • https://dpt-mh.com/uploads/news/files/patufujekesejedoded.pdfIn PDF document text
    • http://huspanda.com/data/ckfinder/files/nowugozunususofevijage.pdfIn PDF document text
    • http://rioairporttransfer.com/ckfinder/userfiles/files/wexeremanad.pdfIn PDF document text
    • https://lidiyageorgieva.com/ckfinder/userfiles/files/73367245056.pdfIn PDF document text
    • http://kayamedbursa.com/userfiles/file/21349849374.pdfIn PDF document text
    • http://naturabliskociebie.pl/userfiles/file/xeveje.pdfIn PDF document text
    • https://astdubai.co/userfiles/files/61828055157.pdfIn PDF document text
    • http://oio.cn/uploadfiles/files/bubuzezunefinarodufubin.pdfIn PDF document text
    • http://www.egavilanes.com/ckfinder/userfiles/files/voviniwejotune.pdfIn PDF document text
    • http://seoaudytor.pl/userfiles/file/mibore.pdfIn PDF document text
    • http://www.predia.cz/userfiles/file/xovuxitawebubajinogu.pdfIn PDF document text
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/1612f31fa53bed---vobisarapamapalujug.pdfIn PDF document text
    • http://abbeytraining.net/userfiles/file/kazirigibeja.pdfIn PDF document text
    • http://rockpapersun.com/upload_mce_image/file/31009440872.pdfIn PDF document text
    • https://medbioplast.com/klucharnet/images/file/88608712713.pdfIn PDF document text
    • http://juditphotography.com/picture/userfiles/file/zedefesaruvis.pdfIn PDF document text
    • http://otestmanager.org/club/data/userfiles/file/20210904004527.pdfIn PDF document text
    • https://www.dooleysnaturalgas.com/ckfinder/userfiles/files/24803277357.pdfIn PDF document text
    • https://ph2020.org/ckfinder/userfiles/files/tijajil.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=android+link+contactsPDF 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_off0000adda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xADDA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c5ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5EC 16636 bytes
SHA-256: fa6e21824bfdf7d579cd1b3b1134cd4d62845e772bdfca57f3bdf7b9eae8a2c3
font_02_sfnt_off0000eee5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEE5 10304 bytes
SHA-256: 1897a6dc97fb18820335bca8500de83e83902eb2f1b1603c397550fe5f5ef525