Date: 19 August 2003
References: ESB-2003.0313 ESB-2003.0525 AU-2003.010 AU-2003.011 ESB-2003.0561 ESB-2003.0580
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AUSCERT External Security Bulletin Redistribution
ESB-2003.0579 -- Trend Micro Medium Risk Virus Alert
WORM_MSBLAST.D (W32/Welchia, W32/Nachi)
19 August 2003
AusCERT Security Bulletin Summary
Operating System: Microsoft Windows Server 2003
Microsoft Windows XP
Microsoft Windows 2000
Microsoft Windows NT 4.0
Impact: Execute Arbitrary Code/Commands
Delete Arbitrary Files
Access Required: Remote
CVE Names: CAN-2003-0352, CAN-2003-0109
Comment: For more information, please see:
This new variant exploits specifically targets Windows XP with
the original DCOM RPC vulnerability (that Blaster also targeted
per AU-2003.011) via TCP port 135. In addition, the worm also
targets computers running Microsoft IIS 5.0 with the previous
WebDav vulnerability (described in AL-2003.02) via TCP port 80.
Reports to AusCERT indicate that the greatest impact of this
worm is the denial-of-service condition that occurs within
organisations due to high levels of ICMP traffic the worm
generates to find active machines to infect.
AusCERT has published an article "Protecting your computer from
malicious code" which provides advice for protecting the PC desk
top environment from malicious code for home users, SMEs or
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TrendLabs HQ received numerous infection reports of a new malware named WORM_MSBLAST.D
spreading in Japan, Taiwan, and Singapore. It currently has an infection count of 20,000.
A yellow alert has been called at 7:14 AM, August 18, 2003 (US Pacific Time)
to stop the spread of this malware.
It usually arrives as DLLHOST.EXE (~10,240 bytes) and opens port 707, for its malicious routines. Similar to
the earlier MSBLAST worm variants, this malware also exploits the RPC DCOM Buffer Overflow,
and instructs target systems to download its copy from the affected system using the TFTP program.
TrendLabs HQ has released the following EPS deliverables:
- - TMCM Outbreak Prevention Policy 47
- - Official Pattern Release 614
- - Damage Cleanup Template 161
Please inform us if there are any infection reports in your region.
For more information on WORM_MSBLAST.D please visit our Web site at:
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