Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c74d2c9c7d99de2…

MALICIOUS

PDF

238.3 KB Created: 2021-07-08 03:20:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 2458dfabf67dc80b47badd9769c7ffb1 SHA-1: ac9ad09c92e563ffd12f7af62b63e906d1e50558 SHA-256: 3c74d2c9c7d99de2bf9e5a8e2512a6afb6d7e82867b45aa377a18f2ba6de651d
134 Risk Score

Malware Insights

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

The sample is a malicious PDF, identified by ClamAV and an ML classifier, containing embedded JavaScript. This script likely attempts to exploit vulnerabilities within the PDF reader to execute further malicious code. The PDF also contains a link farm pointing to compromised WordPress sites, suggesting an attempt to host and distribute additional malicious payloads, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9928

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://vinacomvietnam.vn/uploads/news_file/75617339122.pdf In PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bf4e2701fd6---44584652923.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160bf404b3f874---8560952620.pdfIn PDF document text
    • https://www.enterpriselighting.com/wp-content/plugins/super-forms/uploads/php/files/08cd73da157f25be8abe44943515d043/waluvejuri.pdfIn PDF document text
    • https://www.freshstartdigitalmarketing.com/wp-content/plugins/super-forms/uploads/php/files/4ec0b1dd77a0c2d072f1d963e540fd96/26627019880.pdfIn PDF document text
    • http://meetburgerusa.com/uploads/files/76773607424.pdfIn PDF document text
    • http://pospatrans.cz/UserFiles/File/2094084097.pdfIn PDF document text
    • https://corumosmanlimakina.com/js/ckfinder/userfiles/files/14841218098.pdfIn PDF document text
    • https://tort-art.ru/userfiles/file/sivonulobudamokazaruk.pdfIn PDF document text
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/ee47fdc416f327a9dc1849f472a66f03/72448324455.pdfIn PDF document text
    • https://www.straightmyteeth.com/wp-content/plugins/super-forms/uploads/php/files/dc071a3d3499b50b36916abd7f881d40/64252980734.pdfIn PDF document text
    • https://hse.tw/upload/file/60279006943.pdfIn PDF document text
    • http://nuraski.pl/wsg/userfiles/kukanikiwup.pdfIn PDF document text
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/13bcde7fdd4635333619c4c339598074/pudiduva.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609fc79aac3fd---69848675163.pdfIn PDF document text
    • https://mobilieroccasion.fr/uploads/file/bomatode.pdfIn PDF document text
    • http://syuncyoku.jp/upload/file/45348620112.pdfIn PDF document text
    • http://henri-ruch.ch/doc_pub/file/tesupam.pdfIn PDF document text
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/16071b0ae05c2f---38918613397.pdfIn PDF document text
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/91dbc87b310d303bec3f1e5aef077aeb/fukune.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160b2a1c620877---nexivepurajutawojosom.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/d094f776a395aee9e78bf1a658e23c98/21312399821.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=color+coordinated+quotesPDF 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_off00034d46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x34D46 17168 bytes
SHA-256: ee713fadc70501b430f703c2a40bb8cec375abcfad052b74bb352724866c4527
font_01_sfnt_off00037973.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x37973 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0003918a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x3918A 10640 bytes
SHA-256: 30a378c6b585886e0807155fd851c7034178e5806e1a3782cef982bb61b977f0