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Sasser worm

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Ok, so a worm exploiting the Windows problem in LSASS.EXE process (that was patch a couple weeks ago in MS04-011) is out, called Sasser. Here's the MS page on it:
http://tinyurl.com/39hae
The antivirus companies all have updates for it by now (3AM CST Sunday morning; can't sleep, so I thought I would read up on it). There are links and article popping up on it all over.
Just wanted to throw a heads up out there.
The current reports (again, at this late hour here) state that it's not spreading insanely fast (no Blater or -- even worse, Slammmer -- speeds), but it is moving around.
It attacks TCP port 445 (SMB port), so it is Win2K/XP/2K3 only. No 9x line, nor NT4. So, that alone will make its impact less than Blaster. But it's still moving out there.
I'm worried about work on Monday, those laptop users coming into the office in the morning, plugging in, bypassing the firewalls and virus scans and IDS egress filters, etc.
I don't expect to have a good day Monday.
This patch, MS04-011, has some documented problems (you can read about the problems here: http://support.microsoft.com/?kbid=841382), so I know my company has NOT rolled this patch out full-scale yet. My web servers are patched (due to the SSL vulnerability the patch also fixes), but that's about it.
Ok. Good luck to all! I hope you are more patched against this one then my machines are!

20 replies

by thechas

Thanks for the heads up.

I thought it was a bit unusual to get a new virus definition update on a Saturday.

That must mean that the A-V companies consider this a fairly serious issue.

Hope you were able to get some rest.

Chas

by thechas

This MUST be serious!

McAfee just sent out another update to their AV software today.
On a Sunday!!

I may wait until mid-day to boot up my system at work tomorrow.

Chas

by maxwell edison

.
Thanks a bunch for this - and all the other "heads-ups" you give us. You are always on top of these kinds of things.

by oz_media

I just finished two full system restores in a row.
Ad it turned out after each restore, it would come back again, even while first installing and recognizing hardware.

I had Colin email me a copy of lsass because in the time I could actually boot and go onlie 1-5 minutes, I found it wasn't one of three wroms it was attributed to, and MSKB said you could replace the corrucpted lsass file from disk.

It turned out to be the hotels server/routers AGAIN, after their netadmin reset, everything was fine. (Had the front desk call the netadmin at home, that took some frustrating efforts too)

I needed to get a report and invoice done right away too so it was a rush issue, i got shut down just as I was posting to Tech Q&A so I didn't bother again.

by oz_media

I failed to thank you for passing on the information, I am patching now, THANKS!!!!

by joseph moore

Oz, how bad was this one for you? Did your machines go into a constant reboot, or did they just reboot once, when the infection happened? I've read conflicting reports on this. Some say there is one reboot, when the worm hits you and infects you; you reboot, then stay up, but you are infected and the worm routing is running, scanning and trying to infect others.
And other posts are saying that they get stuck in a constant reboot cycle.
So, which did you experience?

Other then that, Symantec has version B of Sasser at a Category 4, which is the highest level they every put things at (Blaster, MyDoom, Slammer, CodeRed were all Cat 4).

And I read on F-Secure's site that they have a version C that will spawn over 1000 connection thread attempts when it looks for other machines to infect. Sasser A and B only spawn 100 threads for scanning/infecting other machines. With 1000 connection threads on version C, that's gonna bring down firewalls due to the sheer amount of traffic they are trying to filter.

Yes, and you all know this is just gonna get worse Monday (although I guess it's already Monday in Australia, HK, Japan, etc.)

BTW, I did finally get to sleep at a little past 4AM! Let's hope we all get some rest, for tomorrow will not be good, and we all need our rest!

by oz_media

Firstly, it was my stand alone laptop that I was trying to finish some work on before meeting a friend for a drink at the hotel.

Let's see, I was in the hotel before dinner and was watching a live feed from Fraser Downs, my triactor was looking good and the field was pacing as predicted when I got the 59 second shut down error. The race was 2:01 so I missed it! That's where I got pissed off.

SO I reboot, same thing after a few minutes. Some reboots lasted long enough for a quick Deja search and save to favorites. Then I'd reboot, hit favorites and search for my answer frantically. Sometimes it was during log on then it would be OK for 10 minutes.

I read about BLaster, didn;t sound right but i managed to run a BLaster fix which found nothing.

Another issue was related to service pack upgrades or the security level being change, not applicable (ooops reboot again).

After a while, I managed to find some info from MSKB about renaming and extracting the original lsass.exe from the Win disk. My backup was at home and my copy of Win2K was there also, (this machine only has a restore option from the partition so I have a burned Win2K disk for such file extraction needs).

I managed to get an emial out to Colin asking for the file but without being able to stay online it is hard to continuously check email especially from somewhere 8 hours ahead, thank god Colin's a night owl.

Needing to get work done NOW, I performed (the computer did anyway) a complete rebuild and I was onine in 30 minutes. As the drivers were being installed by the setup program, it asks to go online and check IBM for the latest, at that point the error started again.

Once again, I reformatted and restored,as it wasn't properly setup. This time all the preinstalled drivers went in fine and I didn't log in to update. All was fine whil I got my work done and I went online again to send it to my client, as I pressed send, the 59 seconds started again (NOTE: Colin HAD replied in this time already but it was too late and he could only find some XP files that probably wouldn't have worked but I had given up before then anyhow, THANKS AGAIN COLIN!!).

I called the reception desk and the night guy, who probably didn't know how to change the channels on the TV he was glued to put up a bit of a fight but eventually called the manager and had him contact their IT guy, (I went to the bar).

On the way back up to my room, the fellow at the desk pulled his attention from his TV long enough to tell me that the IT guy had found a problem in their server that was tracking usage and performing the SMDR for the CDR call accounting system, so he rebppoted his server and routers and all seemed OK. I assume it had been hit by this worm and he will probably be fixing it now if it is reinfected already.

As for myself, everything is working well EXCEPT micrsoft. First I could get to the patch description but not the file. THen I couldn't get to the KB articles at all and now even the homepage won't work. Have they been hit too even though they know about the vulnerability or are they just being hammered by users trying to patch?

If anyone's got this file on disk I'd appreciate a copy by email ( ozmedia@xxcite.com ) but if not, I'll just hope for the best and wait.

It seems to be a relatively simple single key regedit if you are hit now anyway.

by voldar

Joseph, I just find out about this worm. I had some problems with the computer - rebooting like somene tried to shut it down from remote control - and I checked on the net, and yes, sasser is the one that did that.
I used for myself STINGER, and it did the job, and thanks to you, I found the patch also.
Thanks again, and hope you'll not have the same problems.
For any interested, here is my log file I get after using stinger:
McAfee AVERT Stinger Version 2.2.4 built on May 2 2004

Copyright (C) 2004 Networks Associates Technology, Inc. All Rights Reserved.

Virus data file v1000 created on May 2 2004.

Ready to scan for 41 viruses, trojans and variants.

Scan initiated on Sun May 02 00:57:22 2004

C:\WINDOWS\avserve2.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\avserve2.exe has been deleted.
C:\WINDOWS\system32\1132_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\1132_up.exe has been deleted.
C:\WINDOWS\system32\13058_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\13058_up.exe has been deleted.
C:\WINDOWS\system32\13228_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\13228_up.exe has been deleted.
C:\WINDOWS\system32\1375_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\1375_up.exe has been deleted.
C:\WINDOWS\system32\13817_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\13817_up.exe has been deleted.
C:\WINDOWS\system32\14504_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\14504_up.exe has been deleted.
C:\WINDOWS\system32\19091_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\19091_up.exe has been deleted.
C:\WINDOWS\system32\23743_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\23743_up.exe has been deleted.
C:\WINDOWS\system32\24990_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\24990_up.exe has been deleted.
C:\WINDOWS\system32\25246_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\25246_up.exe has been deleted.
C:\WINDOWS\system32\2573_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\2573_up.exe has been deleted.
C:\WINDOWS\system32\26987_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\26987_up.exe has been deleted.
C:\WINDOWS\system32\27339_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\27339_up.exe has been deleted.
C:\WINDOWS\system32\29171_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\29171_up.exe has been deleted.
C:\WINDOWS\system32\29697_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\29697_up.exe has been deleted.
C:\WINDOWS\system32\3054_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\3054_up.exe has been deleted.
C:\WINDOWS\system32\30713_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\30713_up.exe has been deleted.
C:\WINDOWS\system32\3183_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\3183_up.exe has been deleted.
C:\WINDOWS\system32\32568_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\32568_up.exe has been deleted.
C:\WINDOWS\system32\3835_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\3835_up.exe has been deleted.
C:\WINDOWS\system32\4218_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\4218_up.exe has been deleted.
C:\WINDOWS\system32\4319_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\4319_up.exe has been deleted.
C:\WINDOWS\system32\5640_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\5640_up.exe has been deleted.
C:\WINDOWS\system32\6427_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\6427_up.exe has been deleted.
C:\WINDOWS\system32\7166_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\7166_up.exe has been deleted.
C:\WINDOWS\system32\785_up.exe
Found the W32/Sasser.worm.b virus !!!
C:\WINDOWS\system32\785_up.exe has been deleted.
D:\winasp.exe\winasp.exe
Found the Exploit-DcomRpc.gen trojan !!!
D:\winasp.exe\winasp.exe has been deleted.

by oz_media

From what I read, although they both exploit the same hole, they are very different in nature of effects though, I think.

I am just really embarassed to have been hit with this in an evening when I wasn't prepared as I usually am for these things. Away from home and in need to get work done. Mind you, I never would have been hit at home, friggin' unstable hotel networks!

Well, I'm over it now and i think better off for it as I was having some recent program issues from a dodgy install. Things are much better now anyway, so ecen though it was quite an inconvenience, I must thank the exploiter for pushing me to get things running well again.

OM

by mrafrohead

I figured that I would also include the SNORT sigs should you use SNORT. These sigs are compliments of Martin Overton. I am posting them from a mailing list that I am a part of. I figured that this may help some of us our there...

------------BEGIN SIGS HERE--------------------

alert tcp $EXTERNAL_NET any -> $HOME_NET any (msg:"W32/Sasser.worm.a
[NAI])"; content:"|BC 3B 74 0B 50 8B 3D E8 46 A7 3D 09 85 B8 F8 CD 76 40
DE 7C 5B 5C D7 2A A8 E8 58 75 62 96 25 24|"; classtype:misc-
activity;rev:1;)

alert tcp $EXTERNAL_NET any -> $HOME_NET any (msg:"W32/Sasser.worm.b
[NAI])"; content:"|58 BC 0C FF 59 57 32 31 BD EC 34 64 6E D6 E3 8D 65 04
68 58 62 79 DF D8 2C 25 6A B5 28 BA 13 74|"; classtype:misc-
activity;rev:1;)

---------------END SIGS HERE--------------------

by mrafrohead

Another thing I guess I should post...

MS04-011 update can break your Windoze. It does have some flaws in it. Me personally, I installed it on my Server at home, but not on my workstations. It is causing problems with long boot times during startup, and also making my sound card not work on one of my boxes.

If you run into problems, you can uninstall the patch labeled: KB835732.

If you DONT use this patch, you NEED to make sure you have a firewall set to block ports TCP 5554, 445 and 9996.

Good luck.

by joseph moore

Here is a Technet article on some of the problems with this patch:
http://support.microsoft.com/?kbid=841382
Ever since this patch came out, there have been a lot of posts with people having problems with it. The majority of the problems I've read about (but not experienced personally on any of my test machines) involve the CPU hitting 100% usage on the SYSTEM process.
So, you can't just roll this patch out and expect all to be fine. Patch, and HOPE all will be fine!

by mrafrohead

There is a reg entry that is created when the virus infects your box to abstain from rebooting. Your machine should not start to reboot itself once you are infected. It should just try to keep sending information and infect other machines.

by mrafrohead

Alright, I guess I'm spoon feading y'all garbage...

Here's a quote from Wired:

"When a machine is infected, error messages may appear and the computer may reboot repeatedly."

So, I still stand by my comment, there's code there to keep it from rebooting, BUT Windoze was coded to work, and it doesn't always, so I guess I have to reneg on my previous post.

Sorry for the missinformation.

by oz_media

There is an entry to DISABLE the user from shutting down or rebooting.
By showing a damaged lass.exe file the system doesn't see the user as having sufficient rights to reboot.

The registry entry you spoke of is a VERY simple singkle-key delete that resolves the issue.

Unfortunately, when I was infected I was still in a hotel, and it was THEIR server that was screwed.

At this point, nobody had posted the fix or removal tools or even an up to date signature.

As it was a reasonably fresh system boot, the MSKB was not yet offering the patch in Windows update but only through a separate KB download.

"What a difference a day makes!!" ONE FREAKIN' DAY!!!!! "24 stinkin' little hours!!"

argh,

But things are running like a well oiled machine now, (bad term for computers I suppose).

I also have a desktop, I JUST upped to Win2K.
Everything went SO well and worked SO fantastic. Somewhere in the MS updates, it has picked up an intermittent stack dump.

I have disabled the system reboot but haven't seen the error again yet for debugging.

Oh well, that's Microsnot for ya.

by mrafrohead

I've read a ton on this patch where they reference NT4 SP6 and it's bugs. I guess MS04-011 is right along the same lines in it's buggieness...

I wish that they would hurry up and rerelease it with a fix, so I could patch up my opened boxes... ;p

Mrafrohead

by coreypi

Hey, thanks for heads up! By any chance do you know how to block or close TCP port manually?

Thanks

by joseph moore

>how to block or close TCP port manually?

Easy. A process/application/program listens on a specific port, as per its programming.
So, to "close" a port, you just STOP whatever process/application/program that is listening on that port! Even ports that are used by the operating system still fall in this category.
For example, with the Sasser worm, it attacks port 445, the Windows SMB port.
So, to "close" port 445 on a Windows box, you stop the file sharing functionality in Windows, i.e. stop the file sharing process. If Windows is not doing file sharing, then port 445 will not be "open" in this sense.
But ports are not just "open" by themselves. A program listens on that port, so that is what makes the port open.

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