Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf23ca7578a26cba…

MALICIOUS

PDF

71.4 KB Created: 2021-09-27 08:01:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 95364fca0ededa7695bbf15256720f94 SHA-1: 0ba61bd1d06aac996c32e7f46f2463cfa9aadcb8 SHA-256: cf23ca7578a26cba9d3f49a8d2352a16becb0d5df64d934f9e0c756aacaf21b1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised websites and disposable hosting, suggesting an attempt to lure users to malicious content. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9893

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/161435aad4bb33---68811162483.pdf In PDF document text
    • https://cordovajewelry.com/images/file/55923273951.pdfIn PDF document text
    • http://lse.hu/userfiles/file/72055264085.pdfIn PDF document text
    • http://spain-ex.com/images/blog/file/97024354407.pdfIn PDF document text
    • https://mklaassen.nl/images/file/11262463867.pdfIn PDF document text
    • http://xn----0tbbbfo0f.xn--p1ai/userfiles/file/67855501209.pdfIn PDF document text
    • https://hotelpancharatna.com/assets/userfiles/files/vonomifebodafegusavofa.pdfIn PDF document text
    • http://ilsungwarehouse.com/userData/ebizro_board/file/jitoronojajorikazidepara.pdfIn PDF document text
    • http://ohmamakitchen.com/uploads/files/vezuzup.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16137fdb034872---70145729120.pdfIn PDF document text
    • http://tavaszitura.eu/userfiles/files/xawamiwudujiz.pdfIn PDF document text
    • https://ngonluathan.com/images/ckeditor/files/vofilod.pdfIn PDF document text
    • http://yushendesign.com/images_fck/file/1631835106.pdfIn PDF document text
    • http://kirakuramenandsushi.com/uploads/files/14408328614.pdfIn PDF document text
    • http://fasson.vip/images/editor/files/42229758897.pdfIn PDF document text
    • https://crmsaas.dswip.com/ci/userfiles/files/17392189150.pdfIn PDF document text
    • http://www.injamal.es/nueva/ckfinder/userfiles/files/mavexarexir.pdfIn PDF document text
    • http://aquamedia.cn/ckfinder/userfiles/files/26223536793.pdfIn PDF document text
    • https://seeandhearbetter.ie/img/shop/contents/35900648374.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/9498222c9052524858f3822c96bda0db/wirusun.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/00uadcthrkkj6hfb3csraohul3/zetuvofinojisige.pdfIn PDF document text
    • http://montpellier-businessplan.fr/mbp/upload/images/images/upload/ckfinder/69370239822.pdfIn PDF document text
    • http://xn--90afqerdlt1f.xn--p1ai/admin/ckfinder/userfiles/files/96278409578.pdfIn PDF document text
    • http://neoneofytou.com/ckfinder/userfiles/files/naxapi.pdfIn PDF document text
    • http://skolicka.eu/foto/images/file/jukodixulubiduvakifofi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=coloring+fun+mod+apkPDF link annotation
    • https://b2cdemo.tickets.com/content/files/jamijatojakadadifafal.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_off0000b418.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB418 10668 bytes
SHA-256: 8c081110595f58736e6f48a82b816159778d47f9170b75eceae6d4bb20bba791
font_01_sfnt_off0000cc3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC3A 17332 bytes
SHA-256: 7734e530c1209ce966eb291b9ac4eb66bd56ee3b75aad0cfed825ed0c0065a4d
font_02_sfnt_off0000f82c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF82C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1