Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7a9b524af8e6608…

MALICIOUS

PDF

82.8 KB Created: 2021-07-08 18:22:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: ec41e725af76879ef014122571c2a039 SHA-1: 830414dfb8fd5e50f6cb38e4defc5cfde5c5562c SHA-256: a7a9b524af8e6608e9dd153dff493a2b443ac1ce7ab2a10a42327c0d857a1511
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and a large number of external links, many pointing to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely serves to download or redirect to a secondary payload, while the link farm aims to obscure the true destination and potentially engage in SEO manipulation for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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.
  • 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
  • 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://www.emmabowman.com/wp-content/plugins/super-forms/uploads/php/files/7ffd94f39c8fea5f34e292a321877fbe/xuruloxez.pdf In PDF document text
    • https://terravistahometeam.com/wp-content/plugins/super-forms/uploads/php/files/432e5ff2cc5840a5388a68047aabde5d/logepefabe.pdfIn PDF document text
    • https://www.reflectionuk.com/wp-content/plugins/super-forms/uploads/php/files/joa6ihrapsckrstmbn608ap74d/gawupij.pdfIn PDF document text
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/860c40047843ca8892b0424bc031e6dc/kilidodafi.pdfIn PDF document text
    • http://ville-dammarie.com/ckfinder/userfiles/files/lebobem.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce929277d7---susumiropi.pdfIn PDF document text
    • http://beijingxinzhi.com/userfiles/file/20210513194627_1059622844.pdfIn PDF document text
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/81471670895.pdfIn PDF document text
    • http://xn----7sbab1bcaqplb0ccyi9d.xn--p1ai/files/file/wewet.pdfIn PDF document text
    • http://davidlbrooks.com/clients/868292/File/mibamejeduzunobe.pdfIn PDF document text
    • http://agendaalzheimer.org/files/galeria/files/470525669.pdfIn PDF document text
    • http://feynburg-uhren.de/uploads/wusadunovalamus.pdfIn PDF document text
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/fbbjt2kcirp4uoeuoeheidk83c/latupibukirukibaw.pdfIn PDF document text
    • https://www.olympusnorge.no/wp-content/plugins/super-forms/uploads/php/files/v24nom4eekf6j6q0519qq7r7ls/mozode.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607988ba872fc---55381061936.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/76a3d3a7f1974b95cbbedd11f5c7dbab/88584049114.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dda2cd6011e---jupaxakaxixixibazeg.pdfIn PDF document text
    • http://lexus-custom.com/js/upload/files/69004613638.pdfIn PDF document text
    • http://kondicionery-vidnoe.ru/upload_picture/file/sufewomijit.pdfIn PDF document text
    • http://cnokorea.com/userfiles/file/jemujexubikakegix.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/85b3c99f1ec351fac7b41f8d3aff646b/zagapetadaderinil.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/160850b4ad5237---86384488343.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf624543615---7287259162.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4654c82307---lidogup.pdfIn PDF document text
    • http://angelojrobles.com/admin_initial_test/userfiles/file/59934649728.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=translating+words+into+algebraic+expressions+worksheetPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#Referenced by PDF JavaScript
    • http://purl.org/dc/elements/1.1/Referenced by PDF JavaScript
    • http://ns.adobe.com/pdf/1.3/Referenced by PDF JavaScript
    • http://ns.adobe.com/xap/1.0/Referenced by PDF JavaScript
    • http://ns.adobe.com/xap/1.0/mm/Referenced by PDF JavaScript
    • http://ns.adobe.com/xap/1.0/rights/Referenced by PDF JavaScript
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF6F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f786.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF786 11176 bytes
SHA-256: dcc3187bd38bdc38d5f99cd5b52c00078066470aec279534cc86639ee7233f81
font_02_sfnt_off00011141.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11141 16920 bytes
SHA-256: 362f2df62c3e14b3f1570a9f6653877f244c34689ecbf47db6b36433e2b0e674