GKCTF2021-Misc

签到

下载后发现是一个流量包，大致浏览后就是攻击者通过tmpshell.php执行系统命令

在http流5中发现cat flag命令

不过响应包的一大串字符我不知道该怎么处理，查了wp才知道这是hex编码

我们将这串编码hex解码->base64解码得到

又卡住了，继续看wp得知，这是每行数据都做了reverse处理，例如看最后一行，等号本该在后边，此时却在最前边，我们写个脚本将数据还原成reverse之前的模样

a='wIDIgACIgACIgAyIK0wIjMyIjMyIjMyIjMyIjMyIjMyIjMyIjMyIjMyIjMyIjMyIjMyIjMiCNoQD'
b='jMyIjMyIjMyIjMyIjMyIjMyIjMyIjMyIjMyIjoQDjACIgACIgACIggDM6EDM6AjMgAzMtMDMtEjM'
c='t0SLt0SLt0SLt0SLt0SLt0SLt0SLt0SLt0SLt0SLt0SLt0SLt0SLt0SLt0iCNMyIjMyIjMyIjMyI'
d='6AjMgAzMtMDMtEjMwIjO0eZ62ep5K0wKrQWYwVGdv5EItAiM1Aydl5mK6M6jlfpqnrQDt0SLt0SL'
e='t0SLt0SLt0SLt0SLt0SLt0SLt0SLt0SLt0SLt0SLt0SLt0SLt0SLK0AIdZavo75mlvlCNMTM6EDM'
f='z0yMw0SMyAjM6Q7lpb7lmrQDrsCZhBXZ09mTg0CIyUDI3VmbqozoPW+lqeuCN0SLt0SLt0SLt0SL'
g='sxWZld1V913e7d2ZhFGbsZmZg0lp9iunbW+Wg0lp9iunbW+Wg0lp9iunbW+WK0wMxoTMwoDMyACM'
h='DN0QDN0QDlWazNXMx0Wbf9lRGRDNDN0ard0Rf9VZl1WbwADIdRampDKilvFIdRampDKilvVKpM2Y'
i='==QIhM0QDN0Q'
print(a[::-1])
print(b[::-1])
print(c[::-1])
print(d[::-1])
print(e[::-1])
print(f[::-1])
print(g[::-1])
print(h[::-1])
print(i[::-1])