Malicious PDF — malware analysis report

Static analysis result for SHA-256 9805618dca56fa33…

MALICIOUS

PDF

89.3 KB Created: 2021-06-29 10:03:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5a120ae302b2415a2f27ed8224f9ab0d SHA-1: 5a8338507753491ba5493186694f612d56e934b3 SHA-256: 9805618dca56fa33ca4fe7ee914a846d3e12935da589ebaf7a86bada1ac04e9e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links pointing to websites hosted on compromised CMS upload storage and disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but containing embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://greenvalleykerala.com/ckfinder/userfiles/files/xunajapumutu.pdf
    • http://nesthomes.in/userfiles/file/rametamivobibu.pdf
    • http://www.parkwaytransplant.com/media_upload/upload/files/jifam.pdf
    • http://trhs64.com/clients/c/cf/cfad56e582d93fa9eda51f2516e23bdb/File/67327233731.pdf
    • http://plenaadoracao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ac909280416---zubedibuvubopuranumazuto.pdf
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094b82ca702c---80667888030.pdf
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d64ae0e3a6c---74578324464.pdf
    • https://an-professional.ru/img/files/file/dedepijozigixofosowa.pdf
    • http://www.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e3a92289ae---30735713899.pdf
    • http://kledingindex.nl/images/uploads/16158779844.pdf
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/54ffe717258ffd805bf51f4043dca826/dodiduposokonejele.pdf
    • https://munord.com/wp-content/plugins/super-forms/uploads/php/files/0e07c9d6f89233b24e87deeb1c05b95e/gukukebobipuxunedadap.pdf
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608c224a193c7---73444781479.pdf
    • https://addsfly.com/userfiles/file/mesulajovutaguzeturati.pdf
    • http://coffee33.ru/archive/file/64550020745.pdf
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/2be74d197660eef1150c5d14a46ce078/mowir.pdf
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/ef672ef281df64a7558cd5ce523d943d/95808476183.pdf
    • https://sitebyside.ru/wp-content/plugins/super-forms/uploads/php/files/da54076b553e02695d045c74aaf4da67/34512970912.pdf
    • http://abaj.cz/UserFiles/File/88616073684.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609d51c1dffbd---xopunuvoboritekotasajen.pdf
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d01aaa0433---28357908216.pdf
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097e10ad0a54---841632490.pdf
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1609b8c0005a8f---11990235033.pdf
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609aa7a11df5a---7304462226.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=what+is+the+most+reactive+element+in+group+1
    • 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_off0000f817.bin
2e63a53aa2b207377df46a1a19a3fc245e2c96052b26fc369c70aaab4e5ade9b
pdf-font-stream PDF embedded font (sfnt) at offset 0xF817 17528 bytes
font_01_sfnt_off00012619.bin
f7665ba9d6075607b8ec23a1cfd0138ec6a2c490d022a15142ae45e9ceff1c24
pdf-font-stream PDF embedded font (sfnt) at offset 0x12619 11032 bytes
font_02_sfnt_off00013faf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13FAF 16792 bytes