Malicious PDF — malware analysis report

Static analysis result for SHA-256 24f217d9d019487d…

MALICIOUS

PDF

70.0 KB Created: 2021-10-02 22:03:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 0e7a0ab09699383867fd622adb0892fc SHA-1: 8c4de1c8dc09ff6a793a0862580bd0d08318bf2e SHA-256: 24f217d9d019487defa441e571e380d6aac9fc64f958518fe532775c99c8ef12
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but serving as a vessel for the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://cructi.ru/uplcv?utm_term=twins+born+at+different+times PDF link annotation
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/64664f7f2cf6d28af90ba8da8e71d6c3/74648068056.pdfIn PDF document text
    • http://pizzeria-millemiglia.de/app/webroot/img/editor/file/52865457903.pdfIn PDF document text
    • https://chiataiec.com/userfiles/Proj_Name/files/80739158891.pdfIn PDF document text
    • http://ledins.lv/cms/file/60041719501.pdfIn PDF document text
    • https://dolaodong.com/userfiles/file/zadabagetozobuxalos.pdfIn PDF document text
    • https://comobrew.com/newsite/images/user_uploads/file/92455592824.pdfIn PDF document text
    • http://thainightjob.com/ckfinder/userfiles/files/33032311422.pdfIn PDF document text
    • http://domexpo.ru/up/file/29304426973.pdfIn PDF document text
    • http://raffaelecavazzoni.com/userfiles/files/lesululolow.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141fdc3d5cef---78433358166.pdfIn PDF document text
    • https://oceanflowerhotel.com/uploads/image/files/bupepez.pdfIn PDF document text
    • https://mai-avto.ru/upload_files/file/wulunupe.pdfIn PDF document text
    • http://thietkeweblongan.com/upload/files/vikilitanudepowiran.pdfIn PDF document text
    • http://swatimishra.in/uploaded_files/userfiles/files/23136074458.pdfIn PDF document text
    • http://edmo-cars.nl/images/file/99436051317.pdfIn PDF document text
    • http://domadoma.cz/userfiles/file/tagedelefu.pdfIn PDF document text
    • http://syuncyoku.jp/upload/file/13837425070.pdfIn PDF document text
    • https://investmentskillsgroup.com/images/userfiles/file/98744561258.pdfIn PDF document text
    • http://jumpinfit.it/userfiles/files/sululimosoliw.pdfIn PDF document text
    • http://eventologia.com/userfiles/files/soruvenejibi.pdfIn PDF document text
    • http://kondicionery-lobnya.ru/upload_picture/file/mapepixusajatexoxabagoban.pdfIn PDF document text
    • http://www.alfapilates.pl/upload/file/bugukevusaniju.pdfIn PDF document text
    • http://ottotech.center/userfiles/file/momejal.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a165fd5abd---58421272957.pdfIn PDF document text
    • 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_off0000b20c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB20C 15552 bytes
SHA-256: e061b108bcea210e8849d59b49e9b94afc84891a39a93ac57a0767dad66e6570
font_01_sfnt_off0000d985.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD985 10660 bytes
SHA-256: 697a305ef78036ab3ae2bd9b69edd9a9b5530ec72bc4b95d6e095f8ebe161589
font_02_sfnt_off0000f209.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF209 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1