aerinndis
join:2008-08-27
| [Help] Syncflood attack on Belkin
I have been getting hundreds of syncflood attacks the last three days and it's cutting me off of the internet, sometimes for hours. I have tried searching to find a fix for this problem and I don't understand the answers, I need it spelled out in layman's terms.
Belkin doesn't seem to have a whole lot in the way of features. My cousin said to enable stateful packet inspection but of course this Belkin crap doesn't have it. I tried updating the firmware as someone on MajorGeeks suggested saying that it worked. It didn't work and my whole firewall log got erased. I'm going to post here what is in my firewall log just since the router rebooted itself. The most predominant IP I looked up and it's Akron, Ohio but I was told it's probably a spoofed IP.
Found Syncflood attack from 76.244.157.122 in port 43691 => Sun Jun 14 04:09:22 2009
Found Syncflood attack from 61.147.107.56 in port 2967 => Sun Jun 14 04:09:22 2009
Found Syncflood attack from 76.244.157.122 in port 43691 => Sun Jun 14 04:19:11 2009
Found Syncflood attack from 76.244.157.122 in port 43691 => Sun Jun 14 04:19:41 2009
Found Syncflood attack from 76.244.157.122 in port 43691 => Sun Jun 14 04:27:25 2009
Found Syncflood attack from 76.244.157.122 in port 43691 => Sun Jun 14 04:27:55 2009
Found Syncflood attack from 125.65.112.217 in port 8000 => Sun Jun 14 04:32:02 2009
Found Syncflood attack from 125.65.112.217 in port 7212 => Sun Jun 14 04:32:02 2009
Found Syncflood attack from 125.65.112.217 in port 3128 => Sun Jun 14 04:32:02 2009
Found Syncflood attack from 76.244.157.122 in port 43691 => Sun Jun 14 04:33:34 2009
Found PortScanner attack from 64.22.131.8 in port 1774 => Sun Jun 14 04:38:12 2009
Found Syncflood attack from 76.244.157.122 in port 43691 => Sun Jun 14 04:42:20 2009
Found Syncflood attack from 76.244.157.122 in port 43691 => Sun Jun 14 04:48:31 2009
Found Syncflood attack from 76.244.157.122 in port 43691 => Sun Jun 14 04:49:01 2009
Found Syncflood attack from 76.244.157.122 in port 43691 => Sun Jun 14 04:58:49 2009
Found Syncflood attack from 76.244.157.122 in port 43691 => Sun Jun 14 05:10:11 2009
Found Syncflood attack from 61.160.216.187 in port 7212 => Sun Jun 14 05:13:16 2009
Found Syncflood attack from 61.160.216.187 in port 8000 => Sun Jun 14 05:13:16 2009
Found Syncflood attack from 76.244.157.122 in port 43691 => Sun Jun 14 05:21:00 2009
Found Syncflood attack from 76.244.157.122 in port 43691 => Sun Jun 14 05:21:30 2009
Found Syncflood attack from 76.244.157.122 in port 43691 => Sun Jun 14 05:29:45 2009
Is there something in the router settings I can do to stop this? I don't even know what any of it means, had to google syncflood lol. |
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aerinndis
join:2008-08-27
| Ok I turned off the modem and unhooked everything and left it that way for an hour so it would release it's IP and get a new one when I turned it back on. It gave me the same exact IP and I have at least 100 more of these attacks. There's also a crapload of "get IP" and WAN disconnection messages......exactly every 11 seconds on the dot. Time Warner said it's not their problem since the attacking IP's aren't one of their customers. |
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sashwa
Pixie Cat Crunchin' n Foldin'
Premium,Mod
join:2001-01-29
Alcatraz
clubs:  | reply to aerinndis
Let's move you over to our Security Forum and see if you can get some help in there.
Good luck.
 |
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Its a Secret
Whatever
Premium
join:2008-02-23
U B Funny
1 edit | reply to aerinndis
First off, stop logging the attacks, it may help. Close your ports if any are open. Are you using p2p? If so, shut it down and see if it stops.
When this happens to me, they bounce and I don't miss a beat for uptime. |
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aerinndis
join:2008-08-27 | reply to aerinndis
The router logs them automatically, I can't stop it. There is no function on Belkin to close ports so that's not a possibility. What is P2P? If you mean file sharing then no, I have never downloaded mp3's or anything else. |
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sivran
Long Live The Suite
Premium
join:2003-09-15
Arlington, TX
clubs:
 ·RoadRunner Cable
| A port's default state is closed, and would only be open in the case of user (or malware) or UPNP intervention.
There's nothing like an "Enable Logging" checkbox?
What model router is it? A quick look at portforward.com shows Belkin routers tend to store port settings under "Virtual Servers" within the web ui.
--
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no warrants shall issue, but upon profitable cause... |
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aerinndis
join:2008-08-27
| I've been all through the menu, I can't find anything like enable logging. I'm using Belkin G Wireless F5D9230-4. There is a virtual server menu but it has a drop down list of programs to choose from, they all look like games. Then you pick the port you want to run the program through. It's not like my old Netgear router where I could open and close ports at will. This Belkin really has no features. My cousin said to enable stateful packet inspection but this router does not have that feature.
There are literally hundreds more of those syncflood attacks since I last posted. I can only assume they're not getting past the NAT firewall and these people will eventually give up. I went through all of the IP's and did a Whois lookup and emailed all of their ISP's. The ones coming from AT&T and some other one in LA stopped immediately, but new ones popped up to take their place. The Chinese ones did absolutely nothing. I feel like I'm being targeted. I know lots of people commonly scan ports but I've never seen anything like this.
That site you posted is interesting but their port checker only checks one at a time. With thousands of ports, that would be very time consuming. Wouldn't Steve Gibson's GRC Shield's Up be a better way of checking ports? |
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Its a Secret
Whatever
Premium
join:2008-02-23
U B Funny
·Shaw
1 edit | GRC would give you a better clue as to what's up. As well, do you run a SW firewall? It would be good if you did. Comodo, Online Armour, and Zone Alarm are good.
Is there a firmware update for your router? You may want to change routers if all else fails.
fookin' typos!
--
"In the future, that which is not mandatory will be illegal"
"Nobody knows the age of the human race, but everybody agrees that it is old enough to know better" - Anonymous |
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NetFixer
Freedom is NOT Free
Premium
join:2004-06-24
Murfreesboro, TN
 ·Vonage
 ·Cingular Wireless
·AT&T CallVantage
 ·AT&T Southeast
| reply to aerinndis
I suspect that you already know this, but your only likely remedy is to buy a real router.
The synflood packets by themselves do not usually take up much bandwidth. The likely reason that your internet connection is being affected is that your brain dead Belkin router is still making NAT table entries for each incoming synflood packet (even though it has already diagnosed them as synflood packets). When the available memory for NAT table entries is used up, your internet connection is then blocked. That is why this kind of probe is called a "denial of service" attack. I had to dump a D-Link DI-LB604 router for this same kind of behavior. My current Cisco/Linksys RV082 just laughs at DDoS attacks and keeps on trucking.
--
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander. |
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aerinndis
join:2008-08-27
| reply to Its a Secret
I just went to GRC and all of my ports are stealth, up to 1096 that is. I had to manually check the others because as you can see from my log, they are going for high numbered ones. There is no known protocol for port 43691, why are they probing it?
Yes I am using Comodo, the free version and also Avira for a/v protection. I can't speak for the guy downstairs....I don't think he uses anything and it's his router lol. If my ports are stealth and someone is syncflooding, does that mean my IP got picked up somewhere on a site and made it onto a hacker's list?
I did just update the firmware in hopes of stopping this or at least getting some extra features to use in the menu but there wasn't much else added that was useful. What makes me laugh is how Belkin's update button tells me there is no newer firmware but when I manually check their site I find a much newer one. I also read some other ppl had the same complaint. Their firmware updates also don't tell you what was added or changed which is also very irritating. I just think Belkin is a crappy company. |
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Its a Secret
Whatever
Premium
join:2008-02-23
U B Funny
·Shaw
| Whoa! You're leeching off your neighbor's router, and you did a wireless FW update?! Bad idea, as it could pooch the router.
He's the one getting hit, not you. Get your own connection, dude.
--
"In the future, that which is not mandatory will be illegal"
"Nobody knows the age of the human race, but everybody agrees that it is old enough to know better" - Anonymous |
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Woody79_00
join:2004-07-08
united state
| reply to aerinndis
Yes i think what is happening is the routers NAT table is getting full and once the memory runs out it blocks the internet aka DOS as another poster mentioned.
In most cases, contacting the ISP of the offending IP is most likely usless unless your some big company. The IPs are most likely spoofed IP's anyways.
It is most likely those asian spammers from over in China and other places. My PfSense box gets "tons" of hits a day...many SQL exploit attempts and other garbage coming from there.
Luckily Snort with the latest definiions from Sourcefire bans their IP's left and right...its a constant battle.
I heard there was a vulnrability in "some" Router models from Belkin, Linksys and a few others that would allow a remote attack to bypass the router with specifically crafted packets...I am not sure what model of routers they are, but i do believe Steve Gibson at GRC.com has a webpage about it, the models listed, and even a test to see if your router is vulnerable.
Good luck to you, I would personally try getting a better router maybe...it seems they are intent in keeping you offline. If you have an old computer around, IPcop, PfSense, or Monowall could probably handle this for you. If that is too complicated for you, you could try buying an upgraded router model at a local store. one that has more memory and is on the higher end may better handle such an attack. |
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Woody79_00
join:2004-07-08
united state | reply to aerinndis
oh your leeching of your neighbors connection?
nevermind my previous post then
go get your own connection man! |
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Its a Secret
Whatever
Premium
join:2008-02-23
U B Funny | Yea, the height of audacity...  |
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aerinndis
join:2008-08-27
| Excuse me, I didn't say I was stealing anything. He bought the router so I can have internet up here. He owns the house and I am living in the upstairs part of it. I developed a disability last year and am unable to work. Applying for Social Security is a long painful process. He knows I'm up here, he bought the router for that purpose, he gave me his WEP key.
Now moving on. Would it be easier for him to call Time Warner and ask for a different IP? It's supposed to be dynamic but when we turn it off for an hour or so it picks up the same IP it had before. I thought it was supposed to flush out the old IP after being off a certain amount of time and just pick up a new one. Is the attack on the wireless router specifically or is it on his roadrunner modem? I can't really tell. |
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Its a Secret
Whatever
Premium
join:2008-02-23
U B Funny | If you're using WEP, you're probably feeding the 'hood. WTF, man... |
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aerinndis
join:2008-08-27 | I don't know what you mean by that but the DHCP client list only shows our computers on the network. If we were not WEP enabled then everybody in the "hood" would be feeding off of us, as you so eloquently referred to my neighborhood as. |
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Its a Secret
Whatever
Premium
join:2008-02-23
U B Funny | Use WPA2, it's backwards compatible to WPA, and far more secure. Use a 63 ASCII character PW from GRC: »https://www.grc.com/passwords.htm |
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NetFixer
Freedom is NOT Free
Premium
join:2004-06-24
Murfreesboro, TN
·Vonage
·Cingular Wireless
·AT&T CallVantage
·AT&T Southeast
1 edit | reply to aerinndis
said by aerinndis  :Would it be easier for him to call Time Warner and ask for a different IP? It's supposed to be dynamic but when we turn it off for an hour or so it picks up the same IP it had before. I thought it was supposed to flush out the old IP after being off a certain amount of time and just pick up a new one. Is the attack on the wireless router specifically or is it on his roadrunner modem? I can't really tell. Most cable internet suppliers will reuse the same IP for the same connecting device unless it is left disconnected for a very long time (like a week or more). You may be able to "clone" your PC's MAC address into the Belkin routers WAN, and that should force a new WAN IP to be assigned to you (after you make the MAC address change and power cycle the cable modem).
If your landlord is doing P2P traffic (since you say that you are not doing that), that may be what is attracting what the Belkin router is interpreting as synflood traffic, and changing the WAN IP address will not help. The attacker(s) may also just be scanning a large IP subnet for routers and servers to use as slaves in a "reflection" synflood attack, and once again, changing the WAN IP address will not help. Without actually knowing anything about what your Belkin router is calling a synflood attack, any speculation would be just that.
--
We can never have enough of nature.
We need to witness our own limits transgressed, and some life pasturing freely where we never wander. |
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sivran
Long Live The Suite
Premium
join:2003-09-15
Arlington, TX
clubs:
·RoadRunner Cable
| said by NetFixer :Most cable internet suppliers will reuse the same IP for the same connecting device unless it is left disconnected for a very long time (like a week or more). You may be able to "clone" your PC's MAC address into the Belkin routers WAN, and that should force a new WAN IP to be assigned to you (after you make the MAC address change and power cycle the cable modem). Slight caveat to that - it may just flat out break the internet access. Last time I swapped routers, power-cycling did not restore access. I had to clone the MAC from the previous router.
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The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no warrants shall issue, but upon profitable cause... |
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