Malicious PDF — malware analysis report

Static analysis result for SHA-256 fc755ca839b3054f…

MALICIOUS

PDF

71.8 KB Created: 2021-10-01 03:05:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: e13172523917832dfa3e1cc270bd0b61 SHA-1: bbc1f250ff3c81fc418c079a27c6dc2f326efb4b SHA-256: fc755ca839b3054ff829699bee551466b01c876bbb1f0f91de5dbfa0e925c75e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, with one specifically pointing to 'synerhu.ru' and a 'shell shockers download' UTM term, indicating a lure for users to visit a potentially malicious site. The PDF's structure and the presence of many external links suggest it functions as a link farm designed to redirect users to phishing or malware distribution sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://synerhu.ru/uplcv?utm_term=shell+shockers+download PDF link annotation
    • https://r4binsh4h9-att.com/contents/files/59011772163.pdfIn PDF document text
    • http://rebornfair.com/FileData/ckfinder/files/20210929_86391B723CA60B66.pdfIn PDF document text
    • http://nowator-zpu.pl/userfiles/file/89226804125.pdfIn PDF document text
    • http://smileorganic.net/smileorgfarm/filesupload/File/56367275010.pdfIn PDF document text
    • http://www.morrisjones.co.uk/EditorImages/file/zasadefekofefuragirexuk.pdfIn PDF document text
    • http://rungrawin-itt.com/userfiles/files/94851940439.pdfIn PDF document text
    • http://ekstelekom.com/userfiles/file/63706113439.pdfIn PDF document text
    • https://dammesliepas.lv/ckfinder/userfiles/files/62114545663.pdfIn PDF document text
    • http://dsacare.com/admin/uploads/file/83012930885.pdfIn PDF document text
    • https://ximatinhdongnai.com/app/webroot/files/images/pages/files/57222019173.pdfIn PDF document text
    • http://winso.tw/userfiles/file/75039681881.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/16155e7573f5ed---zafuzajase.pdfIn PDF document text
    • https://ewdel.cz/ckfinder/userfiles/files/tililonubewosoxeponur.pdfIn PDF document text
    • https://hssanesteban.cl/files/tinasevesivomamikoxukoj.pdfIn PDF document text
    • https://tgvl.in/uploads/fck/files/pekufugefepapapurowi.pdfIn PDF document text
    • http://speednewslive24.com/assets/ckfinder/core/connector/php/uploads/files/xafijilewibi.pdfIn PDF document text
    • http://arenabilardo.com/data/_files/xemopigolopedune.pdfIn PDF document text
    • http://topimmigrationlawyer.org/ckfinder/userfiles/files/73180442208.pdfIn PDF document text
    • http://ortopediaszombathely.hu/editor_up/56854000134.pdfIn PDF document text
    • http://phelieuviethung.vn/upload/files/44727141370.pdfIn PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141f0c0bb55d---desifogis.pdfIn PDF document text
    • http://newabel.com/ckfinder/userfiles/files/41111013823.pdfIn PDF document text
    • http://dhleisure.com/ckupload/files/92679616876.pdfIn PDF document text
    • http://indianmailbox.com/assets/images/userfiles/files/mukulozozet.pdfIn PDF document text
    • https://www.renfrewareahealthvillage.ca/ckfinder/userfiles/files/33853951641.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_off0000b3c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3C1 17916 bytes
SHA-256: 8cee5d1cd0b805a4dfbed0b7f9ef6385bf1da6e9dec64968017f6086e44c8905
font_01_sfnt_off0000e1c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1C3 10528 bytes
SHA-256: cc1c54c70d0b08bac4e5fe65d8d9800dd323ecdc16a5384df618c8ee7f3553a9
font_02_sfnt_off0000f9ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9CA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1