Fix 3 bugs: date mismatch, duplicate kramdown key, placeholder description

- Fix date in AboutEtherHiding.md: 2025-12-09 → 2025-12-11 to match filename
- Fix duplicate kramdown key in _config.yml that caused math_engine: mathjax
  to be silently overridden (MathJax was not rendering)
- Replace default Chirpy placeholder description with blog-specific description

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Null0RM

_config.yml

@@ -19,7 +19,7 @@ title: nullorm playground # the main title
 tagline: web3 / security # it will display as the subtitle
 
 description: >- # used by seo meta and the atom feed
-  A minimal, responsive and feature-rich Jekyll theme for technical writing.
+  A technical blog covering Web3 security, blockchain internals, and CTF write-ups.
 
 # Fill in the protocol & hostname for your site.
 # E.g. 'https://username.github.io', note that it does not end with a '/'.
@@ -153,13 +153,11 @@ paginate: 10
 baseurl: ""
 
 markdown: kramdown
-kramdown:
-  math_engine: mathjax
-
 
 # ------------ The following options are not recommended to be modified ------------------
 
 kramdown:
+  math_engine: mathjax
   footnote_backlink: "↩︎"
   syntax_highlighter: rouge
   syntax_highlighter_opts: # Rouge Options › https://github.com/jneen/rouge#full-options

_posts/2025-12-11-AboutEtherHiding.md

@@ -1,6 +1,6 @@
 ---
 title: Abusing Web3 - EtherHiding 
-date: 2025-12-09 15:00:00 +0900
+date: 2025-12-11 15:00:00 +0900
 ---
 
 예전에 ENKI에서 발간한 [EtherHiding](https://www.enki.co.kr/media-center/blog/analysis-of-the-clearfake-campaign-using-clickfix-and-etherhiding-techniques)기법에 관한 글을 읽은 적이 있었다. 그러다가 이번에 react에서 CVE 10.0점짜리 react2shell 취약점이 나오며 새롭게 등장한 [react2shell + etherHiding 기법을 합친 북한의 공격](https://www.sysdig.com/blog/etherrat-dprk-uses-novel-ethereum-implant-in-react2shell-attacks)에 대한 글을 읽고, ~~웹서비스보안쪽은 문외한이지만~~ 웹사이트 피싱 등 공격에 블록체인이 사용된다는 안타까움과 함께, 해당 공격 기법에 대해 간략하게나마 공부해보았다.