Malicious PDF — malware analysis report

Static analysis result for SHA-256 ad23b332125397a1…

MALICIOUS

PDF

83.5 KB Created: 2021-09-10 22:16:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 924dcf4ddc07bd67f8fb4f6138603741 SHA-1: 4ca84f2ecca232a699c6c650170b905a0345fb8e SHA-256: ad23b332125397a107d557109bf44ced1b842d8c46de889294560c83b3b34a8e
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. The document contains a link farm with numerous URLs, suggesting an attempt to direct users to malicious content or downloads. While no scripts were directly extracted, the PDF structure and heuristic firings point towards a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9ffbd9884---76591535150.pdf In PDF document text
    • https://sgicorp.com/userfiles/files/8952280682.pdfIn PDF document text
    • https://haisanquangninh.org/data/dulieu/files/18626729880.pdfIn PDF document text
    • https://icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/jusakikapimegifukanedawuz.pdfIn PDF document text
    • https://gadd-asso.org/userfiles/file/58056498517.pdfIn PDF document text
    • https://www.tristar-technology.com/ckfinder/userfiles/files/xuvebevazunukub.pdfIn PDF document text
    • http://braciszewska-klimek.pl/fck_files/file/14025492005.pdfIn PDF document text
    • http://dongshengcable.com/images/upload/File/ferabojafilumari.pdfIn PDF document text
    • http://kiuruvedenlukio.fi/tiedostot/file/ginebadev.pdfIn PDF document text
    • http://novafish.it/userfiles/files/todeguxenuti.pdfIn PDF document text
    • http://avanti.pl/userfiles/file/mosunes.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1613569ff7743d---xaleworozaruzajije.pdfIn PDF document text
    • http://uekekb.ru/!upload/files/52046395918.pdfIn PDF document text
    • http://innotack.com/userfiles/files/71811350928.pdfIn PDF document text
    • http://0851gay.org/userfiles/202109file/2021090711581470554.pdfIn PDF document text
    • https://adamant54.ru/userfiles/files/zavekofoguposixabezajijo.pdfIn PDF document text
    • http://hoangminhceramics.com/app/webroot/uploads/files/xozurusozivavimexazutob.pdfIn PDF document text
    • http://networkinglikepro.com/ckfinder/userfiles/files/gukaloti.pdfIn PDF document text
    • http://kimbuunguyen.com/uploads/userfiles/file/nemagu.pdfIn PDF document text
    • http://thegoshow.net/userfiles/file/53309954159.pdfIn PDF document text
    • http://gaudi.tw/upload/files/54138586232.pdfIn PDF document text
    • http://st-communications.com/ckfinder/userfiles/files/57515144506.pdfIn PDF document text
    • http://harringtonandlombardi.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/42869348011.pdfIn PDF document text
    • https://keepingscore.org/userfiles/file/doxenutubodukexeterowo.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/35933992887.pdfIn PDF document text
    • http://hodori247.com/uploads/files/71224210348.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=train+to+busan+full+movie+123moviesPDF 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_off0000de70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE70 10988 bytes
SHA-256: 67493bfd241ac31aea1c00c0bc6fc4fc18fbc6affb03f5d0be253c797ff467b1
font_01_sfnt_off0000f814.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF814 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011026.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11026 18344 bytes
SHA-256: 4424cb2ad6bbee1fc1d4c2de7182f478d052956221ac097a5059ed4c017d372a