Malicious PDF — malware analysis report

Static analysis result for SHA-256 8101217b6710882e…

MALICIOUS

PDF

87.1 KB Created: 2021-07-04 16:45:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3105c26d2db7351da09ed26455f9d28e SHA-1: cf3857e4b5d93480162de6f1c58ddf77292fb715 SHA-256: 8101217b6710882efcfc408e146bd4b13a81f944a582bd9b2866a2b4c1bb9389
164 Risk Score

Malware Insights

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

The PDF document contains numerous embedded URLs, many of which point to compromised WordPress sites and are structured as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content to analyze.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://alsumiri.net/wp-content/plugins/super-forms/uploads/php/files/b78b2a328abf5ea7ac73a1d755af7b90/rujotosikidujuvovamuwi.pdf
    • https://canadianrelocation.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608e84dd16306---nizofes.pdf
    • http://www.sport-konyv.hu/userfiles/file/beterelagexab.pdf
    • https://www.varisistanbul.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f920c050de---domevonitumizejosazer.pdf
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607500efd3f57---talezareguzasopeb.pdf
    • https://hometeamcorp.com/images/usr/jonopibosugofepukafuv.pdf
    • http://taxilitomerice.cz/ckfinder/userfiles/files/60768006840.pdf
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a01a2ec007b---kalezogaloza.pdf
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a47df4484eb---fufolisadikaxa.pdf
    • https://loctra.net/userfiles/file/96213782561.pdf
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609749e3d7671---gewemilefisok.pdf
    • http://circuitvietnamcambodge.com/hinhanh/file/kijesawugesal.pdf
    • https://savitravel.ro/ckfinder/userfiles/files/litozujab.pdf
    • http://anhbanglaw.com/userfiles/file/zuzutefivojax.pdf
    • http://kiavysocina.cz/UserFiles/File/35751875012.pdf
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085ab296124b---89437970751.pdf
    • http://thesciencenetwork.org/uploads/files/54680105520.pdf
    • http://bearings-home.com/userfiles/file/18521196257.pdf
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb1dce710d---37588701148.pdf
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/16b8158b8ab7b63d64c0e1b0f0a26863/27562728670.pdf
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf44119a7b---27794018975.pdf
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/q9motfockl0vgsukq606681eqt/15074253166.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=quality+of+work+self+appraisal+comments
    • 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_off0000f13f.bin
c19860fd7cfdbb2b143cebbbafe72ccde6d73f0e7e87d374d3ea6655e6e2e125
pdf-font-stream PDF embedded font (sfnt) at offset 0xF13F 16780 bytes
font_01_sfnt_off00011d12.bin
c064cadf3a8b17baa0580990d7201a6efb78b595b3dd89b3512e8f64c2a1f6fe
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D12 11092 bytes
font_02_sfnt_off00013720.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13720 16792 bytes