Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c20b87ebe8d9ba4…

MALICIOUS

PDF

77.7 KB Created: 2021-09-21 11:53:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 3311f89a82e74e8a1e677bd58d31c356 SHA-1: d26c235bd69409a0e64b50e2915b27c9d00fdf94 SHA-256: 8c20b87ebe8d9ba422529541d90ca0b15bb00c8fa44931fd6846146910262c7e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous embedded URLs and is flagged as a link farm on disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a malicious document, likely leveraging embedded JavaScript for malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 5

  • 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.
  • 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=apk+mod+worms+zone+io PDF link annotation
    • https://foodexgida.com/uploads/files/9807052032.pdfIn PDF document text
    • https://ons-station.com/editor_upload/file/xifonesefasubud.pdfIn PDF document text
    • https://nezrenpin.com/calisma2/files/uploads/58509682916.pdfIn PDF document text
    • https://marathonroller.com/userfiles/files/94255330710.pdfIn PDF document text
    • http://tcgardening.com/userfiles/file/2021092110040373499.pdfIn PDF document text
    • http://change4best.ru/upload/file/5167746435.pdfIn PDF document text
    • http://phongkhamthienhoa.vn/images/files/xijebepovowodikakakup.pdfIn PDF document text
    • http://auswallendorf.de/userfiles/file/4501213720.pdfIn PDF document text
    • http://citygclub.com/ckupload/files/23406290772.pdfIn PDF document text
    • http://cjmfgx.morefriendship.com/upload/files/supivanumuwerizitiza.pdfIn PDF document text
    • http://superlitefan.com/uploads/files/telamarakonu.pdfIn PDF document text
    • http://eapver.com/upload/ckimg/files/202109090601272240.pdfIn PDF document text
    • https://hamayeshniroo.com/shop/file/52005952657.pdfIn PDF document text
    • https://pierrelemagicien.com/userfiles/file/93012880735.pdfIn PDF document text
    • https://nieruchomoscikomercyjne.co/files/file/gibuwanetikis.pdfIn PDF document text
    • http://ac-kenigsberg.ru/files/file/1538798452.pdfIn PDF document text
    • http://chataphan.com/file_media/file_image/file/82403648495.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/161329b47223c7---71201216694.pdfIn PDF document text
    • https://nordavril.com/userfiles/file/66754848358.pdfIn PDF document text
    • http://www.radeton-cz.vasestranky.cz/ckfinder/userfiles/files/nurifuzakajolub.pdfIn PDF document text
    • http://bjjiffy.com/upload/naserikelile.pdfIn PDF document text
    • https://autotoner123.com/home/autotone/public_html/ckeditortest_WORKING/ckfinder/userfiles/files/pasodef.pdfIn PDF document text
    • http://massimomoroni.it/userfiles/files/38830142475.pdfIn PDF document text
    • http://hmondo.com/userData/board/file/repewadegefar.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_off0000cc66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC66 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e47d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE47D 10464 bytes
SHA-256: 533b1368696d8195e2e2f834c59335146ca2dfcb503d0ae6098a343d60e27eca
font_02_sfnt_off0000fc4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC4E 17596 bytes
SHA-256: e100bf9d6734ebd4ca2bb325bced17b76e73f73e732abe4e19591484dd9dc965