Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ee755c01c040cc9…

MALICIOUS

PDF

76.8 KB Created: 2021-09-20 23:58:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3a5bb2f179eda294b2504d5cfcd89228 SHA-1: 53f149b22d3ed88f74599b68e5d7447de5805fe7 SHA-256: 4ee755c01c040cc9415bc9851f2eef1f5fa0cf7aa24b4d256306d66d1f8912c6
166 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, with heuristics indicating it's a link farm and a browser installation lure. The document body is heavily obfuscated, but the presence of embedded URLs and the 'SE_BROWSER_INSTALL_LURE' heuristic strongly suggest a social engineering attack. The primary goal appears to be tricking the user into downloading and installing malicious software disguised as a necessary browser update or plugin.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://cocoabuterol.com/upload/files/8748485439.pdf In PDF document text
    • http://sm.ac.th/ckfinder/userfiles/files/sefobusoriz.pdfIn PDF document text
    • http://celyroknaterase.sk/editor_uploads/system/files/simasawawawuwojuke.pdfIn PDF document text
    • https://rmp-familienanzeigen.de/cms/files/78489539509.pdfIn PDF document text
    • http://theofficefurniturestore.com/ckfinder/userfiles/files/51787595666.pdfIn PDF document text
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16144e79e74775---38143415248.pdfIn PDF document text
    • http://hak-al.com/resimler/files/zewewa.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/161380f4b65fa9---59118710605.pdfIn PDF document text
    • https://economiadecomunion.com/ckfinder/userfiles/files/11358725648.pdfIn PDF document text
    • http://heyumpnd.com/userfiles/file///refepaw.pdfIn PDF document text
    • http://www.de.ruben.pl/ckfinder/userfiles/files/xurademokananukejij.pdfIn PDF document text
    • http://derp74.fooden.com/UserFiles/files/43977215583.pdfIn PDF document text
    • http://enslev-anlaegsservice.dk/userfiles/file/4206930647.pdfIn PDF document text
    • http://autohondl.cz/userfiles/file/70498119555.pdfIn PDF document text
    • https://www.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/d4a296dec91f7f56a10af09f44bd2e0e/xewudefopamoxokolirejam.pdfIn PDF document text
    • http://kleinschadenexperte.de/userfiles/file/7114132676.pdfIn PDF document text
    • http://kcemsp.org/upload/editor/file/68641207762.pdfIn PDF document text
    • https://profesa.net/userFilesfile/folin.pdfIn PDF document text
    • http://manenshop.com/upload/files/69918096681.pdfIn PDF document text
    • https://bodymason.com/user_uploads/files/lolup.pdfIn PDF document text
    • http://graciaindoutama.com/kingkong/userfiles/files/lesaregov.pdfIn PDF document text
    • https://kaplaitalia.it/userfiles/files/nezawupiniv.pdfIn PDF document text
    • http://elai.kz/upload/2021/09files/210907161844884191svkog.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=idm+apk+old+versionPDF 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_off0000c7ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7EC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e003.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE003 10564 bytes
SHA-256: eeac261329d9e2a4b47a98de95a38a10af0464ff5fd4decf2bde22bf8c23426c
font_02_sfnt_off0000f805.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF805 17800 bytes
SHA-256: f1b1aa6aa1410c246e0f36a2cc9db819e9207b61397385e978d1895e10b237ea