Malicious PDF — malware analysis report

Static analysis result for SHA-256 1d41b60daf492ef5…

MALICIOUS

PDF

85.5 KB Created: 2021-09-02 13:10:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-01
MD5: 8ba82d32d0fac34ef72888fcd47c976d SHA-1: 77d03031e59eca050b08083c4aa6604078b37ab2 SHA-256: 1d41b60daf492ef5629520f18326251f9e9099334ee425054b2ab68c01728a68
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://bachson.net/upload/file/77562968542.pdf In PDF document text
    • https://fasaac.org/temp/files/rimenojekidulozejek.pdfIn PDF document text
    • http://w-w.cn/isee/pfm/cms/uploadfile/fck/file/53659332163.pdfIn PDF document text
    • http://tcihk.com/userfiles/wofebekajuzajaduwoni.pdfIn PDF document text
    • https://aep-tc.com/cache/fck_files/file/8523257509.pdfIn PDF document text
    • http://xsjsbzrw.com/uploads/files/31072250019.pdfIn PDF document text
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/342f373eeb4fe14f0680fddbc6e5cf8f/tufesomijomovovowijorur.pdfIn PDF document text
    • http://desushibar.com/userfiles/file/timunanavixawenelimokulom.pdfIn PDF document text
    • http://maybaobidinhdinh.com/upload/files/kokifozisaximiwilajesok.pdfIn PDF document text
    • https://cakesandcupcakes.net/userfiles/files/91761282411.pdfIn PDF document text
    • http://goteneplast.se/files/images/file/81743658469.pdfIn PDF document text
    • https://ctners.com/ckfinder/userfiles/files/pesigugepabavebovoxodi.pdfIn PDF document text
    • http://aaz.sk/editor_uploads/files/zenones.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160acfbe68757b---29487790654.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/65554i473k25gk0h1ghakimpl3/32952261350.pdfIn PDF document text
    • http://king-pro.com/userfiles/files/59948860341.pdfIn PDF document text
    • http://mebco.ru/images/file/13268280137.pdfIn PDF document text
    • http://quangcongluc.com/upload/files/nupumajegijikumuz.pdfIn PDF document text
    • http://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba1fc4a0b79---24156638958.pdfIn PDF document text
    • http://anipetkingdom.com/webroot/img/files/36478714831.pdfIn PDF document text
    • https://ghadir-eng.com/userfiles/files/69002672326.pdfIn PDF document text
    • http://eiak.org/upload/editor/files/846207180.pdfIn PDF document text
    • https://golf-tout-terrain.com/publish/page/file/mimutodeninalixisakosa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=reading+books+for+upper+intermediate+level+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_off0000e715.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE715 18060 bytes
SHA-256: 8b761cae930b7f6663ce0b1388bb5fd4fad50f1ca2fad07ee3bdb231d7f9291e
font_01_sfnt_off000115ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115FF 11284 bytes
SHA-256: 8919530f5171651c8429ed8ed2b7527efe128e2542476be85b5f4908734a93a7
font_02_sfnt_off00013012.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13012 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1