Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef3d4ef040047a65…

MALICIOUS

PDF

81.4 KB Created: 2021-10-06 12:31:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: f5e06010ad2d8856ce8562e6c52355ac SHA-1: f1fd8b358197edd047bc2f29a90decd15d3792cb SHA-256: ef3d4ef040047a656b4f9efcb97040391cba3745477f5272bf56e2063bc16ab0
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and a link farm structure. The presence of embedded JavaScript suggests an attempt to execute malicious code, likely for redirection or further payload delivery. The numerous external links, many pointing to PDF files on various domains, indicate a potential phishing or malicious content distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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.
  • 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://aukshanya.promosing.com/alpha/ckfinder/userfiles/files/84582129919.pdf In PDF document text
    • http://makassitools.com/userfiles/file///61896688736.pdfIn PDF document text
    • https://volandovia.it/public/fileeditor/file/lekozegel.pdfIn PDF document text
    • https://trinityautorepairs.com/uploads/files/jobija.pdfIn PDF document text
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/b3cd045fac75464589a63fef0716619f/75689467832.pdfIn PDF document text
    • https://toolsatool.com/userfiles/files/73826985534.pdfIn PDF document text
    • https://vsetinrally.cz/userfiles/file/bepukajaxomuwixowe.pdfIn PDF document text
    • http://cuanhomkinhtoanthang.com/media/file/rijiv.pdfIn PDF document text
    • http://ranjitabiswas.com/userfiles/files/78351496567.pdfIn PDF document text
    • https://vos-web.nl/userfiles/file/gisigezifumupogofupatife.pdfIn PDF document text
    • https://callmarkinvestments.com/callmark/files/xebabovolopazovek.pdfIn PDF document text
    • http://pappteam.hu/userfiles/file/mevewisuf.pdfIn PDF document text
    • https://happyfun.tw/uploads/files/202109220505153654.pdfIn PDF document text
    • http://lidaoxc.com/upload/files/23855437418.pdfIn PDF document text
    • http://cathyourhair.nl/js/ckfinder/userfiles/files/79819738964.pdfIn PDF document text
    • https://designmaster.in/scgtest/eec-new/codelibrary/ckeditor/ckfinder/userfiles/files/4765819665.pdfIn PDF document text
    • http://trendstyleimage.com/uploads/ckfinder/userfiles/files/13634436460.pdfIn PDF document text
    • http://gonzagafood.com/userfiles/files/radimosujuvofamamanavibu.pdfIn PDF document text
    • http://quesnelfoundation.ca/userfiles/file/56880631146.pdfIn PDF document text
    • http://glttek.com/userfiles/file/75016054562.pdfIn PDF document text
    • http://beijingxinzhi.com/userfiles/file/20210903100555_1816529891.pdfIn PDF document text
    • http://tikatalog.sk/_files/file/vokorutop.pdfIn PDF document text
    • http://www.weilandensemble.nl/ckfinder/userfiles/files/nifuvinogerozo.pdfIn PDF document text
    • http://tourgrodno.by/images/content/file/46509268035.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=ffxiv+coral+butterflyPDF 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_off0000d9fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9FD 10556 bytes
SHA-256: bf3d647ab4183840968747760b554e934ecb3b6b124c04b2f51cca68eabace0a
font_01_sfnt_off0000f246.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF246 17868 bytes
SHA-256: 56ff16ff43db10dff71443b18219b7881974baab78c06bd2c3fdc61b68c07e74
font_02_sfnt_off00012000.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12000 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1