Malicious PDF — malware analysis report

Static analysis result for SHA-256 19a43bffb65ef18c…

MALICIOUS

PDF

92.0 KB Created: 2021-08-24 21:46:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 088d627faa938d5e8136ae5cb2414de1 SHA-1: 2c74543b2837c595a3b256ce0920af576ce5be1e SHA-256: 19a43bffb65ef18c7492dce146f23558ba2576cf89e96ddc804670a90a717a84
156 Risk Score

Malware Insights

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

The sample is a PDF document flagged by ClamAV as Pdf.Phishing.Trojan. It contains a link farm pointing to multiple compromised WordPress upload directories, suggesting an attempt to distribute malicious content or phish users. The presence of numerous links on disposable hosting and the use of compromised CMS upload storage indicate a tactic to obscure the true malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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 https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086cfc05695b---10291085783.pdf In PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca16822033---48637546767.pdfIn PDF document text
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608103e669fdf---99843615540.pdfIn PDF document text
    • https://orldoc.ch/wp-content/plugins/super-forms/uploads/php/files/94hkicdccf2712n2c6ct38onv1/xopamaj.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/36002182646.pdfIn PDF document text
    • http://hrzservices.com/uploadfiles/file/fikaxedivanusulavogal.pdfIn PDF document text
    • https://caror.hu/ckfinder/userfiles/files/guxemuvamitumedemomug.pdfIn PDF document text
    • http://conganbacgiang.vn/app/webroot/uploads/files/xigomo.pdfIn PDF document text
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5e0b5648c---91334819831.pdfIn PDF document text
    • https://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/0899083a7881b37733626466fd40035d/tozodidanelitomu.pdfIn PDF document text
    • http://ngocphuocjsc.com/public/default/ckeditor/files/29204279871.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609099b0c3326---31383671962.pdfIn PDF document text
    • http://alliance-ltd.com/userfiles/3610767514.pdfIn PDF document text
    • http://assistance.uz/images/shared/file/rifajukek.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aea1761c077---kolakituxoti.pdfIn PDF document text
    • https://aduanaldelvalle.com/userfiles/file/fatelipapoxonafa.pdfIn PDF document text
    • https://medtek.vn/storage/file/dovobebolomixevesuvusewe.pdfIn PDF document text
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc0046e2578---nofejos.pdfIn PDF document text
    • https://ibericadearmerias.com/file/jalozemelofadum.pdfIn PDF document text
    • https://beruanglucu.com/contents//files/31398652153.pdfIn PDF document text
    • http://gavinlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/73150125485.pdfIn PDF document text
    • https://aashianarealty.com/file/72542150346.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608094d6d53f0---mobonevuvuxipixerujar.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609b52f840d92---puzarip.pdfIn PDF document text
    • http://apsara.ru/userfiles/file/vamilupusibaxaxanafaf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=what+is+common+law+marriage+in+illinoisPDF 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_off00010318.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10318 10756 bytes
SHA-256: cf0ed0ce3691e2d74252297fbd12445b68e027d82b66a1930cd365c671d51fe6
font_01_sfnt_off00011bbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BBE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000133d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133D0 17268 bytes
SHA-256: 3bc97e43cc5fb091ad0b473f65e0ad1dd70cdd63ae83b5d458a4d9a2f1ddb3bf