Malicious PDF — malware analysis report

Static analysis result for SHA-256 3d88489cb9de7c6d…

MALICIOUS

PDF

82.0 KB Created: 2021-09-15 13:38:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 14e795f5458d270757b82ecdc734c763 SHA-1: ea04816d6ae4b20453cea4286babaf7357f01d41 SHA-256: 3d88489cb9de7c6d4ef24c7d9854eebc78ab7a44ca9025fbf67ba8a48ae4f749
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS uploads. The presence of numerous URLs, including those with 'utm_term' parameters suggesting SEO manipulation, points towards a phishing or malware distribution scheme. No scripts were extracted, but the PDF structure itself facilitates the redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 https://synerhu.ru/uplcv?utm_term=the+night+circus+book+pdf+free+download PDF link annotation
    • http://surveycook.com/upload/tmp/202109/file/senofiv.pdfIn PDF document text
    • https://saintarseny.ca/sites/saintarseny.ca/files/file/lekezuf.pdfIn PDF document text
    • http://www.look4job.gr/images/_user_na/file/8310584403.pdfIn PDF document text
    • http://doorsatyrau.com/ckfinder/userfiles/files/pisekewumajulo.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/cida507k0uvaapshi64cj41vro/61068968776.pdfIn PDF document text
    • http://gabinetpro.gabinetpro.pl/kosmetyczka/krakow/files/18222142595.pdfIn PDF document text
    • https://xn--espaoldetalca-lkb.cl/var/www/html/upload/file/8571620027.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613aba246a89f---titiwirujidumi.pdfIn PDF document text
    • https://leo.tw/upload/ckeditor/files/xemifadalawopikad.pdfIn PDF document text
    • https://towa-aaa.jp/userfiles/file/70312234581.pdfIn PDF document text
    • http://controlsystemco.com/cache/fck_files/file/tadifelaful.pdfIn PDF document text
    • http://phutungquanghieu.com/app/webroot/files/ckfinder/files/sefilitanivalimit.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/161345d487d22d---joramuwekobamekik.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/6d3deef940fdd8de7061289db48e8f47/3850151584.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fa7fe33116---58248081933.pdfIn PDF document text
    • http://gewald.ru/content/Files/62350340680.pdfIn PDF document text
    • http://villaturri.it/wp-content/plugins/formcraft/file-upload/server/content/files/16136b9b7a2ec7---rukekikegirune.pdfIn PDF document text
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/7468b22d57909d3c107a28388836b6ac/sewutefawod.pdfIn PDF document text
    • https://laser123.com/geektic/files/61007257107.pdfIn PDF document text
    • http://orderleesushi.com/uploads/files/fomopa.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_off0000d889.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD889 18296 bytes
SHA-256: 091fd3a1f636b5d6bf690e8349856251399205e340d3f4e67a02bfd2584a8864
font_01_sfnt_off00010815.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10815 11280 bytes
SHA-256: b30534fe7f8d722d45df05523ab65d842932f79b9cbe8b87be86f47762f03b26
font_02_sfnt_off0001222c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1222C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1