Malicious PDF — malware analysis report

Static analysis result for SHA-256 b41325d47a3681e0…

MALICIOUS

PDF

106.5 KB Created: 2021-07-21 17:36:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5ced0b3d16ae67768d2632b6293dc757 SHA-1: 75211a8e6bb3febc3c7d819ed9d5ae533b9b10a9 SHA-256: b41325d47a3681e0a0f9b0836519e5b14d438b0e22bd1120d5ac98f7c823a6ee
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Several heuristics point to the PDF being a link farm, with many URLs hosted on compromised WordPress sites, suggesting a phishing or redirection scheme. The document body is unreadable, but the presence of numerous external links and the 'link farm' heuristic strongly suggest the primary purpose is to direct users to potentially malicious external sites.

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 http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c9458ed8da0---fekebepukuferibonemetexo.pdf
    • http://csptech.net/admin/userfiles/file/gedirazufupaguguxaju.pdf
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/16075667c7da11---57099871507.pdf
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a8e17dcb35---62929933119.pdf
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160afbbc2f0c9e---19735099506.pdf
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/bcd78c4fd852579c51a22e57e6db76db/libenijobalemofid.pdf
    • http://xn--80aagkbrca3apkgkee0a1bi.xn--p1ai/ckfinder/userfiles/files/25202214866.pdf
    • http://mamitobe.ru/files/file/ruwivosusugesozaligeguza.pdf
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/pieh1pukjsgcppngjg4j8hdirl/20627443504.pdf
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/991c58e111cf556415ca96e10b225a63/45710247504.pdf
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/83ed829a69b08baa53943b36c9f10a18/8388831149.pdf
    • http://ledins.lv/cms/file/refozutugizowodipow.pdf
    • http://allseasonsart.com/uploads/fck_uploads/file/reronevi.pdf
    • https://advance-pack.com/editor_upload/file/32833645258.pdf
    • http://voijin.com/userfiles/files/27994655246.pdf
    • http://hkt-optics.com/hkt/images/userfiles/file/denujolotabapinodaluwiwas.pdf
    • http://erex.hu/upload/file/bezuzokakup.pdf
    • https://vaytieudungtragop.com.vn/wp-content/plugins/super-forms/uploads/php/files/696jtcsc1tlg141fn8s9041tib/2684570224.pdf
    • http://ieeepes-thailand.org/app/webroot/files/files/31200928288.pdf
    • http://habitat3.eu/userfiles/files/wejusesivegilibetavaponet.pdf
    • http://biomassasia.net/data_ed/userfiles/file/36536976709.pdf
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b3a5afd1cb0---dibafogufuber.pdf
    • https://ozsersogutma.com/upload/files/4387620300.pdf
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6b534718a7---navifaxetikewukisadojele.pdf
    • https://yourlightingbrand.com/wp-content/plugins/super-forms/uploads/php/files/8164631d38cf0227929e5c617e88cc23/7956927962.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=2nd+class+honours+meaning
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013c44.bin
4e5ca8c8efd62ee3c3d5b4a0d78cd6e8b8f501c7c88327c88590bbf75d70b9b4
pdf-font-stream PDF embedded font (sfnt) at offset 0x13C44 10840 bytes
font_01_sfnt_off000154de.bin
bc5bf1e1222546382bfc4ee0e1a146ed2d2129a62c53545dac133abab5c7b7a4
pdf-font-stream PDF embedded font (sfnt) at offset 0x154DE 17728 bytes
font_02_sfnt_off00018376.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x18376 16792 bytes