Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef03cfa3700e7683…

MALICIOUS

PDF

100.6 KB Created: 2021-09-16 15:09:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: e614f50abee409c01794c128a63bce38 SHA-1: 6aee92d3d0760da503dfa3c2724fd76fb40f27bc SHA-256: ef03cfa3700e76836f092481f32bb5be72bd9af830cb876fb9ae9224bada29c1
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was flagged by multiple heuristics, including ML classifiers and ClamAV, indicating malicious intent. It contains an embedded JavaScript stream and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, suggesting it functions as a link farm to distribute phishing content or further malware. The presence of JavaScript indicates an attempt to execute code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9923

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 http://solarexperten.ch/fckeditor/editor/images/file/18205888238.pdf In PDF document text
    • https://dalnoboy.com/data/filestorage/upload/files/68742085392.pdfIn PDF document text
    • http://hrt-foto.hu/_user/file/vixiruvekotaruj.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1614092a738fb4---desakadujidi.pdfIn PDF document text
    • http://tanabuauto.com/js/upload/files/likunirigomoweti.pdfIn PDF document text
    • http://doubles301.jp/files/ckeditor/files/kumuluwobelifotup.pdfIn PDF document text
    • https://kapefashion.com/files/files/61259825201.pdfIn PDF document text
    • http://ardeche.proximeo.com/ckfinder/userfiles/files/1801154267.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/d470bcb5b7e0e439dfa5d6bb31b9dbcc/wukowe.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f8dcce535f---857449945.pdfIn PDF document text
    • http://gzcaifeilai.com/ckfinder/userfiles/files/202109051230251984.pdfIn PDF document text
    • http://emekyesiltepe.net/images_upload/files/luluwedafezapeturaj.pdfIn PDF document text
    • http://illinoislivestock.org/userfiles/file/patuzikinedupinug.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e19257d6ed---24560445250.pdfIn PDF document text
    • http://shopphutungmayphat.com/upload/img/files/febaliwevenurafuvas.pdfIn PDF document text
    • http://www.tecnobor.com/ckfinder/userfiles/files/fajolugelu.pdfIn PDF document text
    • http://rehahomecare.com/upload/editor/files/95217164038.pdfIn PDF document text
    • http://lev-steklo.ru/userfiles/file/lolagilatovo.pdfIn PDF document text
    • https://clubberia.com/js/ckfinder/userfiles/files/ridoxufojiruxakisab.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/92d1407c108c153b3bf81b3085f6c357/rafepola.pdfIn PDF document text
    • https://saint-florentin.charcutier-traiteur.fr/ckfinder/userfiles/files/4805295463.pdfIn PDF document text
    • https://adesso-moosburg.de/images/file/64852493454.pdfIn PDF document text
    • http://cdkuysuujk.handysociality.com/upload/files/26077978384.pdfIn PDF document text
    • https://www.geya99.com/ckfinder/userfiles/files/74560560125.pdfIn PDF document text
    • http://mxagproducts.com/upload/browse/file/6925066969.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=social+media+brandingPDF 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_off00012553.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12553 10660 bytes
SHA-256: 2667423523385536ab3dba5fbd9d6832f2bd7be4d22be2f3969cd64a2133c8e4
font_01_sfnt_off00013d68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D68 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001557a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1557A 18500 bytes
SHA-256: d3fa37e96ce06ae931d10382e23e3cdf70a4a6694130ae7858ee2fe5ccdfc541