Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef541441cd0ba7ab…

MALICIOUS

PDF

92.3 KB Created: 2021-08-03 08:10:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 13f6e624cb713a306264b86171e2355e SHA-1: 6217c1e41249035139cfbf83c29abd3c8356252b SHA-256: ef541441cd0ba7abff77b33175e2d90242adbff8129b2fd52de1856247e28b9e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing numerous links, many of which point to compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically identified as phishing or trojan activity. The embedded links are designed to redirect users to potentially harmful sites, leveraging compromised infrastructure for distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16078912e1ab41---46120063010.pdf In PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072f56e23bb1---79306016695.pdfIn PDF document text
    • https://ariaparvaz.com/basefile/ariaparvazcom/files/62510013052.pdfIn PDF document text
    • http://grafichesirio.com/userfiles/files/nubiremoxuregadume.pdfIn PDF document text
    • http://poorclarescork.ie/images/kadaxal.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160758d5d9b73c---64984812250.pdfIn PDF document text
    • http://sva-jeanroze.com/xmedia/file/bepejegov.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607ea5484fd34---xegarikepepudafuloripogu.pdfIn PDF document text
    • http://kahsport.cz/userfiles/file/sexijelanoraviru.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f9d0be896f---fesujewadogakiwuwi.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c45df5a6c2a---kimotixadafuvepiwafepid.pdfIn PDF document text
    • https://thuaphatlaihoanghuy.com/uploads/files/69152871431.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160787d7497926---25237953234.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16077f5614e1ea---gevijetegujuvo.pdfIn PDF document text
    • http://canoeing.by/pics/files/24459571543.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/6ca7b133j28a6ojhdc8964i607/22384826903.pdfIn PDF document text
    • https://uleshuzataruhaz.hu/files/file/37371650897.pdfIn PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076ec348f115---44680462067.pdfIn PDF document text
    • https://propertiproperty.com/Uploads/userfiles/files/berupevilatojabek.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c0e48683291---17576533933.pdfIn PDF document text
    • https://bleikss.com/userfiles/file/ratevubile.pdfIn PDF document text
    • http://www.publicitymailing.ie/wp-content/plugins/formcraft/file-upload/server/content/files/16071067b1d202---92275596820.pdfIn PDF document text
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/ae2d515206425a8632a4cb9a3f4ac28c/pogefupelet.pdfIn PDF document text
    • https://comobrew.com/newsite/images/user_uploads/file/vazofalisaxogulikusu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=what+is+the+moral+of+the+story+in+the+myth+of+narcissusPDF 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_off0001005b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1005B 10808 bytes
SHA-256: 20fb96d1ff1da101e0d629963e53d1eadbce0ebf5652d5df1738b5af0b6055aa
font_01_sfnt_off00011925.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11925 19824 bytes
SHA-256: b0bcd6409e4df05ba1b94accd93562698329f2f54da844e3c8ed8d61f9102ee2
font_02_sfnt_off00014b2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14B2C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1