Malicious PDF — malware analysis report

Static analysis result for SHA-256 f3cbb6fd1d15f365…

MALICIOUS

PDF

71.7 KB Created: 2021-02-21 15:24:14 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 28b46ff9f56a8100b69f893a979c5a84 SHA-1: dec8c34da3a4f55c65b92f23a90bc86b3eed3ff2 SHA-256: f3cbb6fd1d15f3657cd82447f0ce17ff9f556bb484ef55529be0e71acc52692c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing or spam campaign. It contains a large number of external links, many pointing to PDF files hosted on various domains, suggesting a link farm or SEO spam tactic. The document body, though heavily obfuscated, contains metadata related to 'monomer polymer worksheet key' and the wkhtmltopdf application, which is likely a lure to attract victims to click on the embedded malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://baarspo.ru/123?utm_term=monomer+polymer+worksheet+key
    • https://static.s123-cdn-static.com/uploads/4443337/normal_5fe0d880aef98.pdf
    • https://burerekubexu.weebly.com/uploads/1/3/1/3/131381452/zitiwebapidape_vomin_pepiwavor.pdf
    • https://static.s123-cdn-static.com/uploads/4486054/normal_5ff15cc0c0895.pdf
    • https://cdn-cms.f-static.net/uploads/4380707/normal_60217eabcfbb9.pdf
    • https://bivufinemena.weebly.com/uploads/1/3/1/3/131380184/ef6bbc5e6.pdf
    • https://jaxipalat.weebly.com/uploads/1/3/4/7/134746428/339844.pdf
    • https://xigujevaw.weebly.com/uploads/1/3/4/7/134701692/6796a42.pdf
    • https://static.s123-cdn-static.com/uploads/4379485/normal_5ffb69581d156.pdf
    • https://timifuxi.weebly.com/uploads/1/3/4/6/134676324/telijepudarimitaze.pdf
    • http://boldly-grow.com/43776593567mig0p.pdf
    • https://dolojimopa.weebly.com/uploads/1/3/4/8/134887070/f8ddbb40.pdf
    • https://luxovifawus.weebly.com/uploads/1/3/4/3/134341193/gibovil.pdf
    • https://static.s123-cdn-static.com/uploads/4459921/normal_60091a3bb83ac.pdf
    • http://abanca-electronica.com/pukikamajote442ex.pdf
    • https://fenutirixe.weebly.com/uploads/1/3/4/6/134640366/gowugiz.pdf
    • http://cardio-active.site/wordpress_admin_login_url_change_plugincrtwf.pdf
    • https://cdn-cms.f-static.net/uploads/4444856/normal_5fea3af2e0f9e.pdf
    • https://static.s123-cdn-static.com/uploads/4501361/normal_5fdd0cd448783.pdf
    • https://budamasut.weebly.com/uploads/1/3/4/9/134903336/mepikog.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • 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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000da77.bin
811bf5750b858a401a97ae13428ea533c2ac13718189bddeb31335fab532cf2c		 pdf-font-stream PDF embedded font (sfnt) at offset 0xDA77 5112 bytes
font_01_sfnt_off0000ebd0.bin
b811b71f7dfd9fc5d64e7559d368e020bd87b0c873398a0972692987b6452a1f		 pdf-font-stream PDF embedded font (sfnt) at offset 0xEBD0 10904 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.