Malicious PDF — malware analysis report

Static analysis result for SHA-256 a262399e3a62681c…

MALICIOUS

PDF

75.5 KB Created: 2021-02-22 11:41:24 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 46bae0bef2c7ceb7b07177a84610c155 SHA-1: d0cca649f11659f77e88993bf0ab09d0273d2487 SHA-256: a262399e3a62681cee32d4cb989dc850a59cedd640e76df03db37ebff1860b3d
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of external links, many pointing to PDF files hosted on various domains, suggesting a link farm or redirection mechanism. The document body, though heavily obfuscated, contains metadata indicating it was generated by wkhtmltopdf, a tool often used to create SEO-optimized content that can be used for malicious redirection.

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://bologen.ru/wix?keyword=how+to+glaciers+cause+deposition
    • http://austritkfa.com/zemiravutewulenodo8lfqe.pdf
    • https://tikiruwilowu.weebly.com/uploads/1/3/1/1/131163793/fapobokeb_zemusosobuxukub_depolakazewuno.pdf
    • https://cdn.sqhk.co/libavesonon/TN7idBH/zodevumubavowe.pdf
    • https://cdn.sqhk.co/dudugetogi/ihiP7hj/maxofuganimutomijefoni.pdf
    • https://bifukumuvu.weebly.com/uploads/1/3/5/3/135347201/bikenedotaxeta.pdf
    • https://cdn.sqhk.co/menodotitit/a6fifLQ/35846623560.pdf
    • https://nidiladidubupa.weebly.com/uploads/1/3/4/7/134753920/tegezapo.pdf
    • https://gulapizebulo.weebly.com/uploads/1/3/1/0/131070336/7d2a7a8298.pdf
    • http://golosa-spasibo.ru/18569367844pbnhc.pdf
    • https://cdn.sqhk.co/pezolaje/hmjbhek/mutant_creatures_mod_for_mcpe_addons.pdf
    • http://sale50.pro/52627757098vyypm.pdf
    • https://cdn.sqhk.co/kelulegawi/uhhbjgI/strike_gear_x_shooter_gaming_headset_review.pdf
    • https://pagafamowadaf.weebly.com/uploads/1/3/4/8/134878907/1887247.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/jifedefujodu/51185703716.pdf
    • https://s3.amazonaws.com/gumegulaxi/zatepilazarap.pdf
    • 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_off0000eb84.bin
8257fb0fa6f9ab48a10eb6824702ed4c14b17ff59be34340ac3fb9f9468955dd
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB84 5292 bytes
font_01_sfnt_off0000fdaa.bin
1595673548727f32f7c5843a8712d2d4728a0fa76984663838306691a04fe2db
pdf-font-stream PDF embedded font (sfnt) at offset 0xFDAA 10532 bytes