1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
|
Nigel, Removed isc.incidents.org reference since it is no longer active.
Rule:
--
Sid:
1889
--
Summary:
This event is generated when a web server infected by the slapper worm attempts to send traffic via a communication channel.
--
Impact:
Remote access and potentially denial of service. A slapper worm infection indicates a successful compromise of the host. A communication channel established between infected hosts can be used as a vehicle for a distributed denial of service attack of a target host or network.
--
Detailed Information:
The Apache/mod_ssl worm, also known as slapper, exploits a vulnerability associated with certain versions of OpenSSL. Once a host has been infected by the worm, the worm then attempts to establish a communication channel using UDP port 2002 (both source and destination) to the infecting host. This communication channel is used to create a network for infected hosts to communicate with each other to identify other infected hosts and to deliver attack instructions for other sites.
--
Affected Systems:
Linux hosts running Apache with mod_ssl using SSLv2-enabled OpenSSL 0.9.6d or earlier on Intel x86 architectures.
--
Attack Scenarios:
The communication channel created by the slapper worm allows infected hosts to receive direction from other infected hosts. This can be used, for instance, to coordinate a DDoS attack.
--
Ease of Attack:
Simple. Exploit code exists.
--
False Positives:
None Known.
--
False Negatives:
It has been observed that the port number for the communication channel may vary. Ports 1978 and 4156 have also been seen.
--
Corrective Action:
Apply the appropriate patch or upgrade to the most current version of OpenSSL.
--
Contributors:
Original rule writer unknown.
Sourcefire Research Team
Judy Novak <judy.novak@sourcefire.com>
--
Additional References:
CERT
http://www.cert.org/advisories/CA-2002-27.html
--
|
