Malicious PDF — malware analysis report

Static analysis result for SHA-256 31bec2ab2404f72e…

MALICIOUS

PDF

70.5 KB Created: 2021-06-30 01:35:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 34ad8509c9d65a379a89ccd4ee9eccb3 SHA-1: 4cf054613ad685c6b6662a46b4ce017a5598ea22 SHA-256: 31bec2ab2404f72e6a2b47165c1900fc91b30fc663e9874c1e1f88c70a0f437a
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress upload directories, suggesting a tactic to host malicious content or redirect users. The presence of external URIs and link farms indicates an attempt to direct the user to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://clear-es.net/yamituki-n/uploads/files/71783894469.pdf
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160aa93bd8701b---nilida.pdf
    • https://hopefor.today/wp-content/plugins/super-forms/uploads/php/files/029c8cede10fcd0b7729a75251b3bb8c/91583336703.pdf
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/312ebdca0d5d1562b480f66697b6c0df/baruxomilakeni.pdf
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/r3k2hk1hdt1b45uur58qub5ub7/16824325781.pdf
    • https://advik.net/userfiles/file/dekivapozuvur.pdf
    • https://artenika.pl/fck/file/98584494693.pdf
    • https://www.projectorrentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e0fbce29f8---vibonarolejida.pdf
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/beea223b510f5454bd7f83e28321cb18/jitap.pdf
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/160840a23b69b5---kanedixufanavibitekeleb.pdf
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608dd42eb559f---bobazoromarewisogolerixa.pdf
    • http://foire-fromages-et-vins.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c87390992ab---fiwakurapadinilisowo.pdf
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/30a9c9a2d5f7bf283ab677d3e43df1a9/37749537073.pdf
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/1608cf99f54d2b---tubajowuma.pdf
    • https://www.reachcast.ca/wp-content/plugins/super-forms/uploads/php/files/3e6cbc2cb5acaa3537f3d33afa47ad71/kidozakos.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609dad298c96b---gumagexiv.pdf
    • http://consade.com/userfiles/file/15672332896.pdf
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1607ba110bb01f---wufovabizitulekatetan.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=pdf+1.3+specification
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b521.bin
cdfac7045eab1f788374b26ccce32d22011d20e791c99af5ee5b62be4ef58241
pdf-font-stream PDF embedded font (sfnt) at offset 0xB521 10756 bytes
font_01_sfnt_off0000ce12.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCE12 16792 bytes
font_02_sfnt_off0000e624.bin
6227c6f79282b6738a6e6421dea8e47b7ad1466ec14ea612e6ad84d8a57fbad1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE624 15500 bytes