Malicious PDF — malware analysis report

Static analysis result for SHA-256 f3658b47778da52b…

MALICIOUS

PDF

85.2 KB Created: 2021-09-12 23:22:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f62ee20fb76fac961d9e6e9d794d4a27 SHA-1: eafb0b64c9cbcffebaeec2f396ed1d5bc0c7dfd8 SHA-256: f3658b47778da52bef91dab6b087d5e5b3a59ed16d8b47918b99b17425ef6915
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The presence of numerous embedded URLs, many pointing to compromised CMS uploads or disposable hosting, indicates a link farm designed to lure users to external malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://konberdbio.com/upload/files/53161657536.pdf In PDF document text
    • http://duocthientam.com/uploads/ckfinder/files/6555956742.pdfIn PDF document text
    • https://euro-m.si/web/dokumenti/file/sawogijodirolis.pdfIn PDF document text
    • http://motorlustor.net/userfiles/file/zigubaxebed.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613c9cebcfcac---vijutita.pdfIn PDF document text
    • http://cngwalk.com/fckeditor/userfiles/image/5378412816.pdfIn PDF document text
    • http://hdurmuslar.com/images_upload/files/16445896136.pdfIn PDF document text
    • http://jinshi66.com/uploadfiles/files/powupinutug.pdfIn PDF document text
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613cd782a8643---85440438729.pdfIn PDF document text
    • http://grupafurman.pl/!mag2011/userfiles/file/bapikexidupula.pdfIn PDF document text
    • https://eurosan.pl/user_images/file/9742004826.pdfIn PDF document text
    • http://aunay-sous-auneau.fr/ckfinder/userfiles/files/vetaroduvusowibuloweru.pdfIn PDF document text
    • https://www.acta-mobilier.fr/ckfinder/userfiles/files/gexenobekuzaf.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161395c3625127---xemororip.pdfIn PDF document text
    • https://dodomacnosti.net/data/file/90869874914.pdfIn PDF document text
    • http://topbuild.net/content/xuploadimages/file/14790161215.pdfIn PDF document text
    • http://alltimescare.com/attachment/files/69291692697.pdfIn PDF document text
    • https://redac.ch/upload/71851117808.pdfIn PDF document text
    • https://mimpishio2.net/contents/files/gifezimeverodoximon.pdfIn PDF document text
    • http://uitetenindex.nl/images/uploads/bojifezakolosiwigop.pdfIn PDF document text
    • http://quangcaosmsgiare.com/media/ftp/file/52665322103.pdfIn PDF document text
    • https://asmitahrgroup.com/ckfinder/userfiles/files/74009806847.pdfIn PDF document text
    • http://terezszilvia.com/images/uploaded/file/16828555986.pdfIn PDF document text
    • http://tranhdaquydep.vn/upload/files/mobaz.pdfIn PDF document text
    • http://np-laser.com/upload_fck/file/2021-9-9/20210909022631334719.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=cinebuzz+app+androidPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • 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_off0000ebc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBC7 10404 bytes
SHA-256: 476d238206115f017b4824f9c0ba0fb3b3c2b42d839780caabcda2034400a20e
font_01_sfnt_off00010338.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10338 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011b4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B4A 17180 bytes
SHA-256: d1f2c0c439d81e9d50b46e1b4f9faab6b7ff0b8e215439aa64470056c59caa8d