Malicious PDF — malware analysis report

Static analysis result for SHA-256 c25ba7c686e4eca9…

MALICIOUS

PDF

81.7 KB Created: 2021-10-07 22:53:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 716acdcca075207917df5fd1a6407cc2 SHA-1: a20ace7a3a52d0f2be9905f9857b08ee0b5e6132 SHA-256: c25ba7c686e4eca924e6c6956e5233e54d0160410da87caa3e1246bae13f9f26
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed for malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://krisoc.ru/uplcv?utm_term=rules+of+success PDF link annotation
    • http://wsm.hk/images/uploadfiles/file/27290075639.pdfIn PDF document text
    • https://www.sacict.or.th/ckfinder/userfiles/files/50259833119.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615590ef60d7b---60294469931.pdfIn PDF document text
    • http://studiobonvino.com/userfiles/files/penabupenawas.pdfIn PDF document text
    • http://autoscuolecasetta.it/userfiles/files/75464915335.pdfIn PDF document text
    • http://vdadanang.vn/app/webroot/assets/files/4343923536.pdfIn PDF document text
    • http://lilipoupoli-drama.gr/lilipoupoli/js/ckfinder/userfiles/files/22037268759.pdfIn PDF document text
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/845e03e1da65e7fb7676b1e66cc5e295/83202592814.pdfIn PDF document text
    • http://perfectionistpaintingnj.com/ckfinder/userfiles/files/72983368211.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/16157811b7d11d---70715222546.pdfIn PDF document text
    • http://vinhhangvien.com/upload/files/loverozubus.pdfIn PDF document text
    • http://ihanzao.com/userfiles/file/20210928184910_832308796.pdfIn PDF document text
    • http://kukubara.com/zdjecia/file/49520441382.pdfIn PDF document text
    • http://meijialx.com/ckfinder/userfiles/files/40653160296.pdfIn PDF document text
    • http://xn----8sbnbd9chja.xn--p1ai/userfiles/file/fapupidawa.pdfIn PDF document text
    • https://menokatea.com/ckfinder/userfiles/files/makinevowamomimapojefe.pdfIn PDF document text
    • http://kleinschaden-expert.com/userfiles/file/tafukezidudonuxow.pdfIn PDF document text
    • http://affordableadobe.com/ckfinder/userfiles/files/57136627246.pdfIn PDF document text
    • http://gnox.vn/upload/files/27653792479.pdfIn PDF document text
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/edrkd5bvk10co24sjjbhraj635/zeruserofibutex.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_off0000dcd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCD9 18396 bytes
SHA-256: 45630d787a8e1965cc01ec67642cfc08a880cf2e463067b695b973c17025d5b8
font_01_sfnt_off00010bfa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BFA 9920 bytes
SHA-256: 8739e0f228dd96fbcd93267354b29939e62e37a8779da6aa314731e0662cf570
font_02_sfnt_off0001220d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1220D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1