Malicious PDF — malware analysis report

Static analysis result for SHA-256 28b5e8814f9a2981…

MALICIOUS

PDF

80.5 KB Created: 2021-09-06 13:12:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 91038833452889afc9434a0bd890b049 SHA-1: 7e34194d60c5dea382a4390aa81a70099a8f3776 SHA-256: 28b5e8814f9a298169a411d5445c59374615b366d9455f143bd2e7be45384aba
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm with numerous URLs pointing to various domains, including compromised WordPress sites and disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://clinical-pain.com/pds/userfiles/files/97575450269.pdf In PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/2c9eba11ck7ror7nb5jfugjbb9/48450815216.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f72f4838d8---vumemamevikukozibe.pdfIn PDF document text
    • http://pc-driver.ru/userfiles/files/pigodafujux.pdfIn PDF document text
    • http://esoftland.com/userfiles/file/55015533393.pdfIn PDF document text
    • http://cesnek-vysocina.cz/UserFiles/File/dupefagit.pdfIn PDF document text
    • https://pristineleather.com/userfiles/file/17656304483.pdfIn PDF document text
    • http://asvpp.fr/pdf/44178387288.pdfIn PDF document text
    • http://csptech.net/admin/userfiles/file/kaxadipakosuvavil.pdfIn PDF document text
    • http://quickvideo.nl/userfiles/file/25799894581.pdfIn PDF document text
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/besadomilalisipebopoko.pdfIn PDF document text
    • http://northphoenixmustangs66.com/clients/4/4b/4b49b54eec06ebba3741256e9f3e6f2b/File/fajigabavep.pdfIn PDF document text
    • http://asqcert.net/files/files/99041792439.pdfIn PDF document text
    • http://israel-aliya.com/wp-content/plugins/super-forms/uploads/php/files/aa31f502f1cf949d84a85a42314ce96a/63219707130.pdfIn PDF document text
    • https://ksmt.edu.np/assets/ckfinder/userfiles/files/kibasolugamazelovuzubeje.pdfIn PDF document text
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac41136be8d---fuxaxeko.pdfIn PDF document text
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1bac73c2ac---jurejesanowaneza.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=install+wkhtmltopdf+on+debian+8PDF 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_off0000d1d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1D5 11140 bytes
SHA-256: bad199359eb4fe80867c6389869ef541f2d2c4b75747006cdb4ca74f9c5d36cb
font_01_sfnt_off0000eb79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB79 18460 bytes
SHA-256: 60758e05c074023ee202f2404b4e7ba7bd8149bd66bc520d7aa5452d2db781d9
font_02_sfnt_off00011cb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CB6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1