Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6c341a3729f7327…

MALICIOUS

PDF

77.0 KB Created: 2021-09-22 12:21:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: fe3096c3c8535ba7600785e550cd8f0f SHA-1: 9bf4b0aeea3ed0f8ed9e60d7279cd288c1bd8c76 SHA-256: a6c341a3729f7327bbf755f128401e3c2424e1573aaedad1759be45340e63dbc
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The embedded JavaScript is the primary mechanism for executing malicious actions within the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

Heuristics 7

  • 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.
  • 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://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140225926fbe---21641653239.pdf In PDF document text
    • http://rosritual.su/app/webroot/js/ckfinder/userfiles/files/74839513049.pdfIn PDF document text
    • https://orsam.org.tr/paketler/ckfinder/dosyalar/files/94590673733.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/161369b31d946e---93687577527.pdfIn PDF document text
    • https://matrainagycsalados.hu/userfiles/file/zaxijawifagobebulul.pdfIn PDF document text
    • http://surausa.com/uploads/files/73897193464.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f7a797ab49---59709118973.pdfIn PDF document text
    • http://mwflower.com/upimagesfile///94302837034.pdfIn PDF document text
    • http://palestraarkadia.it/userfiles/files/78987952156.pdfIn PDF document text
    • https://akproauto.com/nbloom/fckuploads/file/kigakukasemakamusezag.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/34698428324.pdfIn PDF document text
    • http://yuli-china.ru/d/files/gemededamelumidek.pdfIn PDF document text
    • http://vlaamspatientenplatform.be/_plugin/ckfinder/userfiles/files/fuwafel.pdfIn PDF document text
    • https://mywayrtk.com/userfiles/file/23982495990.pdfIn PDF document text
    • https://karlschool.org/uploads/files/202109031636453095.pdfIn PDF document text
    • http://kangshi-you.com/uploads/files/202109141351336901.pdfIn PDF document text
    • http://balassalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/koxifenitez.pdfIn PDF document text
    • http://www.jobibon.com/admin/userfiles/file/mipon.pdfIn PDF document text
    • https://alley.52886.tw/uploads/files/jigig.pdfIn PDF document text
    • http://unionasset.net/file_upload/spaw_upload/file/20210908181634.pdfIn PDF document text
    • https://obermeyer-modemarkt.de/upload/file/dijojarubuxemonijiwivepid.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=how+to+put+a+live+wallpaper+on+tabletPDF 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_off0000cb13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB13 16988 bytes
SHA-256: 47de5d915704561627234d79ea9a28c402f0c6dfb44cc3497aa528f0910fdb5d
font_01_sfnt_off0000f710.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF710 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010f27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F27 10460 bytes
SHA-256: c43ca12317c3eef576ca42658598bdf4e987935e41a2e69794c941a5bf66c3c6