Malicious PDF — malware analysis report

Static analysis result for SHA-256 c0a55fc35793e24b…

MALICIOUS

PDF

79.8 KB Created: 2021-09-17 09:47:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 838107eb9a4d19e82ce9418c5baeba93 SHA-1: 4637705c0ddb05fa26a68c4c610682db5e0a1178 SHA-256: c0a55fc35793e24b6cf3d2aeb67aa02ae95b7fdbd8695f8ff56bbb5773d2c7e2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised or disposable hosting, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites, potentially for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://nomylo.ru/uplcv?utm_term=think+and+grow+rich+autosuggestion+pdf PDF link annotation
    • https://madeirashopping.com/userfiles/file/suvumawefexuwidebo.pdfIn PDF document text
    • https://ecohort.info/userfiles/files/bofixurojisadile.pdfIn PDF document text
    • https://flour.co.uk/ckfinder/userfiles/files/sidibofiwebunimewirelow.pdfIn PDF document text
    • https://coloreverything.love/wp-content/plugins/super-forms/uploads/php/files/e6ba4bcef111889b77ddfa3f0dcf311d/zilurev.pdfIn PDF document text
    • http://tech-sub.com/userfiles/file/89251979638.pdfIn PDF document text
    • http://sonarkella.com/userfiles/file/fufazewevorexabinigosa.pdfIn PDF document text
    • https://marblo.com/app/webroot/img/files/xikitubadin.pdfIn PDF document text
    • https://popa.com.br/wp-content/plugins/super-forms/uploads/php/files/b0e66908b931be65f23cd5a17a72550e/bozij.pdfIn PDF document text
    • http://www.beverburcht.nl/upload/files/bepegipegodu.pdfIn PDF document text
    • http://borik.customreal.sk/data/files/3084419307.pdfIn PDF document text
    • http://nena-artspace.com/ckfinder/userfiles/files/fesanu.pdfIn PDF document text
    • http://abwingsva.com/uploads/files/pozuf.pdfIn PDF document text
    • https://villadorottya.hu/uploads/frontend/files/9845238927.pdfIn PDF document text
    • https://expobar.vn/app/webroot/files/images/pages/files/nedexuvemakasugut.pdfIn PDF document text
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/4948417bc822f46fab425e3b647bf79e/6536668115.pdfIn PDF document text
    • https://aqua2go.pl/galeria/file/43031244866.pdfIn PDF document text
    • http://gachbinhduong.com/upload/file/38906433264.pdfIn PDF document text
    • http://fitviewer.com/files/file/18354280716.pdfIn PDF document text
    • http://plechotice.sk/tmp/file/liveneleruvafuvolu.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16134eb3476244---vezegimebavuxi.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_off0000d404.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD404 11096 bytes
SHA-256: 3588149d668527af866cec64fdb8eddde9057d82232388b42c8f8d515f4e21c9
font_01_sfnt_off0000edb2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDB2 17132 bytes
SHA-256: 5f91cc20f23b422bf45effb943697532361fd60e338b9e04a40731c386c5eb19
font_02_sfnt_off0001198c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1198C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1