Malicious PDF — malware analysis report

Static analysis result for SHA-256 6a9c733c4990490d…

MALICIOUS

PDF

79.4 KB Created: 2021-09-08 21:11:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: be19d6cf06ad8c46f81d48b211ea80c7 SHA-1: 350b6d4d1e09a9a47d42666c983c54acf835fb92 SHA-256: 6a9c733c4990490dd30f6cf9b90d8567b4f4e3c545104a9deec020c73b9b4cfd
156 Risk Score

Malware Insights

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

This PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but serving as a vessel for these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 http://jessie.vn/images/ckeditor/files/xuremuvofuja.pdf In PDF document text
    • https://francoisdaulte.com/ckfinder/userfiles/files/21164236286.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/1613173e7cbc76---90149553718.pdfIn PDF document text
    • https://rybczewice.pl/userfiles/file/dukawafumit.pdfIn PDF document text
    • http://archiprojektai.lt/app/webroot/uploads/userfiles/files/76285806006.pdfIn PDF document text
    • https://o-dance.com/upload/files/51496555363.pdfIn PDF document text
    • http://1qjd.com/upload/files/2021-09-01-22-03-17-BHAcuhPQ.pdfIn PDF document text
    • http://kahasat.cz/data/file/11194424968.pdfIn PDF document text
    • https://jin-ji.com/upload/files/56333270715.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132e7dcca3fc---38523002901.pdfIn PDF document text
    • https://global-product.org/CKEdit/upload/files/gubovebenutapa.pdfIn PDF document text
    • http://uptownfallschurch.com/uploads/files/63664459384.pdfIn PDF document text
    • http://aan.kz/ckfinder/userfiles/files/bekilusofuxika.pdfIn PDF document text
    • https://www.jdconstinc.com/ckfinder/userfiles/files/22180862700.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/16135ed639831a---fivoki.pdfIn PDF document text
    • http://inspiredindianfoundation.org/uploads/84787517206.pdfIn PDF document text
    • http://nfraccon.org/userfiles/file/dodipesorasujojesu.pdfIn PDF document text
    • http://www.hkrns.org.hk/ckfinder/userfiles/files/62260139364.pdfIn PDF document text
    • http://muszempilla.com/files/file/26509072704.pdfIn PDF document text
    • https://unique.global/wp-content/plugins/super-forms/uploads/php/files/8df8e1aa4e4b1f02c49a7e7bcd12a708/galeru.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/19d7ae7ef4d8e8f8d89301f3fbf4cfe4/84638673516.pdfIn PDF document text
    • http://cargologicru.com/sadm_files/50062609396.pdfIn PDF document text
    • http://veterinariacomportamentale.it/userfiles/files/xisakumakokinupezewojawa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=police+sub+inspector+circular+2019+pdfPDF 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_off0000ce90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE90 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e6a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6A7 11316 bytes
SHA-256: d75c61286c39bf7cf25eb27bcc0d366a95f92df21ff9d4c94757e6908b25491f
font_02_sfnt_off0001013d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1013D 18180 bytes
SHA-256: 248f4e2c6a1123dee2d15987cdced8616d6ac254af190085f091327403f16bf7