Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4e3c27ca68c8d9e…

MALICIOUS

PDF

84.5 KB Created: 2021-09-17 13:03:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0461b9aba8e8d149025da620ed1473cc SHA-1: 16e01cfbadf37c76f6376497237c371efe913e1c SHA-256: b4e3c27ca68c8d9e3843a9c88809cc6f5cbd25dc6d7d90cf2fa737a19b4be673
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to other PDF files hosted on various domains, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a phishing or downloader attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://tranduongauto.com/app/webroot/files/images/pages/files/gufimurezimarokazam.pdf In PDF document text
    • http://chinazzjx.com/d/files/79913349069.pdfIn PDF document text
    • https://akemi.ro/hirek/file/53492517000.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/161409352156b0---daribuzoguromefonapizozer.pdfIn PDF document text
    • https://snapstudios.ca/userfiles/file/6731035172.pdfIn PDF document text
    • https://immsac.pe/sgi_userfiles/userfiles/files/32321063367.pdfIn PDF document text
    • https://quatden.vn/webroot/img/files/nuvuzuzufuvelumuzovafef.pdfIn PDF document text
    • http://cameranichietsu.com/luutru/files/31192675964.pdfIn PDF document text
    • https://tezerwatch.com/file/upload/files/09-17-04-27-31-24.pdfIn PDF document text
    • http://chineseclothingonline.net/File/23323113077.pdfIn PDF document text
    • http://vinhthuanvietnam.com/upload/files/jotunudasuwazepikejin.pdfIn PDF document text
    • https://psfund.org/public/uploads/files/cms_files/gigukapowabewonazi.pdfIn PDF document text
    • https://dabanbep.tanglehadong.com/upload/files/92204678950.pdfIn PDF document text
    • http://355353.ru/userfiles/file/dibejova.pdfIn PDF document text
    • http://homeopathyhk.com/files/fosubotigofiloguw.pdfIn PDF document text
    • https://www.peeryhotel.com/wp-content/plugins/super-forms/uploads/php/files/de0cd74be8207cf7efee5228d8a5fa9d/lemowogifile.pdfIn PDF document text
    • https://visionbrindes.com/admin/fckeditor/userfiles/file/kupeju.pdfIn PDF document text
    • https://livewireeventz.com/userfiles/file/81295664002.pdfIn PDF document text
    • http://ifap.it/images/file/99759882760.pdfIn PDF document text
    • https://gmnavarra.es/ckeditor/files/56377311133.pdfIn PDF document text
    • https://sanagustin.cl/files/widofakikolafem.pdfIn PDF document text
    • https://willmarareachamber.com/ckfinder/userfiles/files/fabetazukaxunafaba.pdfIn PDF document text
    • http://arabic.cz/ckfinder/userfiles/files/wenanogijokixirenezota.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=0+1+1+2+3+5+8PDF 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_off0000e732.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE732 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ff48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF48 9792 bytes
SHA-256: 7595ae5ebe94e3eb7cf9d48edd9e52df0bce6b4d8cf5fdbb53b9a14e83b91b24
font_02_sfnt_off000114c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114C7 18220 bytes
SHA-256: 7ad9841d935f1e4714b856af62115a09349ca96a1d94ec05e6834613b2cfd3f1