Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd4a167f89f7f673…

MALICIOUS

PDF

89.8 KB Created: 2021-07-03 13:47:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2565a8b55c11d408b9bb7850fdcb3614 SHA-1: d33b8fa0c7f3eb3dee5cd8960960caa4c651efef SHA-256: cd4a167f89f7f673370416d68adeb18250aa5c9f000baaef8fc070ace200702b
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and link farm heuristics, indicating it's designed to redirect users to potentially malicious sites. ClamAV detection as 'Pdf.Phishing.Trojan' and the ML classifier's high score further support its malicious nature. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, rather than user-facing text.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • 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.
  • 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://chcial.ru/uplcv?utm_term=how+breed+horses+in+minecraft
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dee371ac4bd---vegerawupadoxirajowezez.pdf
    • https://irepairplus.nl/app/webroot/files/userfiles/files/pusataz.pdf
    • https://cafesca.mx/ckfinder/userfiles/files/nojisa.pdf
    • http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/076cc5215f29f87d98f9f0feb64fe550/93518015541.pdf
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160a923518e31c---kadutapopizevuditimapatu.pdf
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/ts5gbrg69bugu4r918rfjpfcd7/korofobupepiribelo.pdf
    • http://niestachow.pl/data/aktualnosci_imgs/file/nimedalebile.pdf
    • https://takeorders.online/wp-content/plugins/super-forms/uploads/php/files/utpdrj9dicjtcu2dg9njkb4qcr/paroretumudujajax.pdf
    • http://zigzagontwerp.nl/sites/default/files/file/rodadebiposajafo.pdf
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/046685f9920b303be5012e8a5bd06e28/94271835049.pdf
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/160834c6eeddb3---92367312243.pdf
    • http://davidhammerstein.org/userfiles/file/tafuxeromarorisawe.pdf
    • https://autotronics.vn/userfiles/file/94389566346.pdf
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/6d14984e59e517e5e6ca9d53418e76e1/62877900948.pdf
    • http://cleannshieldflorida.com/wp-content/plugins/super-forms/uploads/php/files/a3d3d361b86903ecc339b891f31fc76d/zuwazipovufifexa.pdf
    • http://deshdunya.com/blogimage/file/fuxoxofef.pdf
    • http://tycoonmedical.com/userfiles/file/dotivorole.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607b2da800456---fizufitobasujijip.pdf
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b5266d7c3a---67818015521.pdf
    • https://bandai-k.com/userfiles/file/difimiponawaninotebogu.pdf
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160c15d38caac0---wusozumokajug.pdf
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078484d5579c---21640181629.pdf
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/336f015ecea07b008990f5a0f6a6a9b7/javelenojesapegurulixaka.pdf
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160cf9fe35f82f---45243137516.pdf
    • 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_off0000fa4c.bin
ea37154ccbfc0ff242570a48326d1d747b619de82e149bd476565447b890e3ff
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA4C 10912 bytes
font_01_sfnt_off00011368.bin
87899f8c601a1536ee44ed392b7538ecf50b0f9cb59db46f858ff2d928b166e6
pdf-font-stream PDF embedded font (sfnt) at offset 0x11368 17636 bytes
font_02_sfnt_off000141e7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x141E7 16792 bytes