Malicious PDF — malware analysis report

Static analysis result for SHA-256 633473d7feb354bb…

MALICIOUS

PDF

70.1 KB Created: 2021-09-04 05:02:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: e792d52c48f72194596674c0e8eb88fc SHA-1: bcb61619159574ebcb4e2715fc51566c5e25c54f SHA-256: 633473d7feb354bb2412db54ada1c8f0977556c36014bb9188f0cf1de8b96a55
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to various domains, many of which are hosted on compromised CMS upload storage or appear to be disposable. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO poisoning to redirect users to malicious content. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://ackerviewguesthouse.com/userfiles/file/libosa.pdf In PDF document text
    • https://aquatrustfina.com/userfiles/file/30794074356.pdfIn PDF document text
    • http://espressobuilders.com/app/webroot/files/userfiles/files/marisanon.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160ab102c174ad---wifulabuxefubizani.pdfIn PDF document text
    • http://kinel-hunter.ru/upfiles/file/49996362711.pdfIn PDF document text
    • https://www.frankreich-ferien.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9f0b66245---22014534243.pdfIn PDF document text
    • https://actaviaserica.org/board/file/files/dexuzosujoliwel.pdfIn PDF document text
    • http://decamiones.com/userfiles/file/43258045006.pdfIn PDF document text
    • https://lastcallslc.com/wp-content/plugins/super-forms/uploads/php/files/174a077b1d41e99f5fb49e20cf6d24a4/91994858763.pdfIn PDF document text
    • http://coinproject.com/userfiles/image/file/94580889919.pdfIn PDF document text
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/kajux.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/1608075b54658a---xuvagalituxivaxuzixasi.pdfIn PDF document text
    • https://somogyplusz.hu/files/kifofidirimo.pdfIn PDF document text
    • http://beerskiboot.de/img/upload/file/zobusikujir.pdfIn PDF document text
    • http://cheapneasytrafficschool.com/CheapNEasyTrafficSchool/pa/trainstation/uploads/image/file/6426729251.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2b16821c3d---gazanekem.pdfIn PDF document text
    • http://agnieszkapawlik.com/userfiles/file/88712394775.pdfIn PDF document text
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/7cd3aa7ac2ae35daf17e1b9b39346886/wufutewidebivarenasiw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=electronics+devices+by+floyd+11th+edition+pdfPDF 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_off0000b06d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB06D 16108 bytes
SHA-256: 4d392e5133482268ea5549cd7ef305e1cfc0978dcb9ab4ae8dc1da6f41adb5be
font_01_sfnt_off0000d9a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9A4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f1bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1BB 10912 bytes
SHA-256: 5bf73331aceb54ed1abf41dd628384b20063d57c6955180ab730399c1e539c75