Malicious PDF — malware analysis report

Static analysis result for SHA-256 b57be017ba731f33…

MALICIOUS

PDF

82.0 KB Created: 2021-09-16 13:54:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 8a124ed6d97e9fa5c9bd0a87e4730393 SHA-1: 635b9f524683f8ef90da3a9047702120ffa48a96 SHA-256: b57be017ba731f33fb09478f8bf3e411b3ddabd9daea3292903c6551fd5f6c46
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, many of which are classified as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or distributing further malware. The presence of an AcroForm button with an action trigger further supports the possibility of user interaction leading to malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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.
  • AcroForm button with action trigger low PDF_ACROFORM_BUTTON
    PDF contains a /Btn form field together with a SubmitForm/URI/Launch/JS trigger — this is the building block of fake 'Download' or 'Open' button overlays used in PDF phishing lures
  • 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://uroci-kursove.com/userfiles/file/93056824710.pdf In PDF document text
    • https://isagrinio.gr/userfiles/89530326586.pdfIn PDF document text
    • http://kustari.net/userfiles/file/82563027288.pdfIn PDF document text
    • https://wintechindia.in/ckfinder/userfiles/files/99266338835.pdfIn PDF document text
    • http://yuanyoujie.vip/userfiles/file/vuronaziti.pdfIn PDF document text
    • https://loyallcanada.net/editor_files/file/fukiditup.pdfIn PDF document text
    • http://ambulatorioveterinarioilprato.eu/userfiles/files/lokezif.pdfIn PDF document text
    • http://assessmentinsight.com/ckfinder/userfiles/files/jixeb.pdfIn PDF document text
    • http://fcraregistration.com/UploadedData/file/vurebukalutifejofisu.pdfIn PDF document text
    • http://barudan.hk/UploadFile/file/20210912094854829.pdfIn PDF document text
    • http://globomax.eu/userfiles/file/besuxejujaluxipejuvosefi.pdfIn PDF document text
    • https://ystechpro.com/nbloom/fckuploads/file/56076151329.pdfIn PDF document text
    • http://nguyenphat.com/public/default/ckeditor/files/dosizarilukofuriw.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16132ef17b26ff---41222126869.pdfIn PDF document text
    • http://soc-in.com/data/media/files/bevidoxaxi.pdfIn PDF document text
    • http://hrt-foto.hu/_user/file/lufobowowemuxavurasim.pdfIn PDF document text
    • http://willettelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/49057682769.pdfIn PDF document text
    • https://daiichitravel.com/uploads/news_file/kuledik.pdfIn PDF document text
    • http://lerucherdesanges.fr/userfiles/file/nakigasisejimowabadoke.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/161305e2421f4b---29440745871.pdfIn PDF document text
    • http://4reality.cz/userfiles/files/duzizokojekudegibumakoko.pdfIn PDF document text
    • http://rund.cz/UserFiles/File/46106141019.pdfIn PDF document text
    • http://marisqueandopremios.com/campannas/file/19457268165.pdfIn PDF document text
    • http://sro52.ru/uploads/files/63649141141.pdfIn PDF document text
    • https://doxity.ro/ckfinder/userfiles/files/tawuburawokojojob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=how+to+get+followers+on+instagram+when+your+account+is+privatePDF 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_off0000d827.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD827 18412 bytes
SHA-256: e4e2f5bb69466d9c0ded7af9a7a1572c40ceab0738f0cefe03d33e5954608689
font_01_sfnt_off0001075e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1075E 11284 bytes
SHA-256: 99b097f444ac8561fb60c1b56dde99264a9dea6921c4f04c29d6db13450bab50
font_02_sfnt_off000121c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121C3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1