Malicious PDF — malware analysis report

Static analysis result for SHA-256 4157023c445d030f…

MALICIOUS

PDF

76.2 KB Created: 2021-08-19 14:54:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: ace245951fd30e4397801454809bbddd SHA-1: f276d15d31ce5a9c8be0b3f84dc2d56edec4eac2 SHA-256: 4157023c445d030f8f01c96700a35f8357b520dbafae4612238f7293730b2276
162 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript, which is a common technique for executing malicious code within PDFs. The presence of numerous external URIs, many pointing to compromised WordPress sites and disposable hosting, suggests a link farm designed to redirect users to malicious content, likely for phishing or malware delivery. ClamAV detection further supports its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6661

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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://www.verimevzabavu.cz/ckfinder/userfiles/files/97286362231.pdf In PDF document text
    • https://www.citysecurity.org.uk/wp-content/plugins/super-forms/uploads/php/files/otmj746buuho56bic8rdbrl7au/82183117854.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/16094d036b4aa8---2604630999.pdfIn PDF document text
    • https://slide-bearing.com/d/files/23680279663.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/16082efd154ad2---jaxovirusapa.pdfIn PDF document text
    • https://humble-brag.com/wp-content/plugins/super-forms/uploads/php/files/6fs5p7sgpav2udv2798d49t53h/25114176325.pdfIn PDF document text
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/160b915af953ac---toletafipanarekubosiji.pdfIn PDF document text
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1611bd5321f871---58031648064.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/1611a09022254b---kagamezitiwuzigofopi.pdfIn PDF document text
    • http://papinchess.ru/userfiles/file/lozevowefawepujamusigep.pdfIn PDF document text
    • https://xn--bankkrtya-41a.hu/js/ckfinder/userfiles/files/xafalot.pdfIn PDF document text
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/f256f0ccae3d8ff93c6c5516497f9f14/99373994048.pdfIn PDF document text
    • http://petukmahaaaraj.com/userfiles/file/44170817931.pdfIn PDF document text
    • http://stphilomenaonline.org/userfiles/file/tubusenotukesabunesut.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160e223fa9792f---86480023027.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160e50ff0ecf77---dawuraxonirijomaxazaruz.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/9t4q9c0sh2n2tvc9hrer97h0j7/mafavizifov.pdfIn PDF document text
    • https://tahubunting1.com/contents//files/41849606458.pdfIn PDF document text
    • http://osrclass1967.com/clients/8/84/84e84eb3bb32f45446e669e24fea3ebc/File/vizelezewofo.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609123cd51b6a---tatedumodiwifabisalo.pdfIn PDF document text
    • http://przyrodnik-kujawy.eu/userfiles/file/67594713377.pdfIn PDF document text
    • https://osikovo.eu/webroot/img/content/files/41993669612.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/dd6dd18ff2b2ee8793cf6ce0ab6b0cd8/89808960777.pdfIn PDF document text
    • http://perseverance.cyou/updatefiles/file/29172997642.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=trace+%C3%A9crite+les+nombres+jusqu%27%C3%A0+999+ce2PDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e16e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE16E 11528 bytes
SHA-256: 360c9ac1124c995ca5a417309d9e19e0bae33dcf136b846664a615c1dee6257c
font_01_sfnt_off0000fc1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC1C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1