× Few antiviral products inadequately detect 3proxy as Trojan.Daemonize, Backdoor.Daemonize, etc and many detect 3proxy as a PUA (potentially unwanted program). It may cause browser warning on download page. 3proxy is not trojan or backdoor and contains no functionality except described in documentation. Clear explanation of this fact is given, for example, in Microsoft's article.

Topic:                    Windows NT/2000 DoS via stream3 flood attack
Authors:                  Dark Zorro <[email protected]>,
                          Error <[email protected]>
Date:                     2 December 2000 (yes... it's old)
Vendor Informed:          2 December 2000
Software affected:        Windows NT 4.0, Windows 2000
Risk:                     Low
Remote:                   Yes
Exploitable:              Yes
SECURITY.NNOV advisories: http://www.security.nnov.ru/advisories


Stream  3 is flood attack of absolutely identical empty TCP packets with
ACK  and  FIN  flags.  Dark  Zoro and Error discovered unpatched Windows
leaks  the  memory  from  non-paged  kernel space during stream 3 attack
against  NetBIOS  (TCP/139)  port. This memory never released back after
attack.  Since  this attack doesn't require TCP connection it may bypass
purely  configured  packet  filters.  Effectivity  of  attack depends on
amount  of  RAM  installed  in  target  host,  routing  schema  and link
bandwidth between source and target (xDSL/10BaseT is ideal). Results may
vary from missing 2-3 Mb of memory from non-paged pool to blue screen.

I've  got few unverified reports of successful usage of stream 3 against
different ports and different systems.


Microsoft was contacted on December, 2 2000. On December, 15 private fix
Q280446  for  Windows  2000  was released. It was made public few months
later and was included into Service Pack 2.

Microsoft failed to reproduce and fix problem under Windows NT 4.0


For  Windows  2000  apply  SP2.  Make  sure  you  filter  all traffic to
privileged ports


stream3o.c  compiles  and  works under i386 FreeBSD. stream3.c should be
more compatible and fast, but not tested.