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SQL Slammer

SQL Slammer, also known as Sapphire and SQL-Hell, is a fast-spreading Internet worm that targeted Microsoft SQL Server 2000 and Microsoft Desktop Engine (MSDE) 2000. It exploited a buffer overrun in the SQL Server 2000 Resolution Service on UDP port 1434, a vulnerability addressed by Microsoft in Security Bulletin MS02-039. The worm propagated by sending crafted packets to vulnerable hosts and was widely reported to have infected 90% of its hosts in less than 10 minutes. Multiple sources in the content describe it as taking out or degrading large portions of the Internet, with reporting at the time noting country-level impact including South Korea. The malware is repeatedly cited as a canonical early-2000s worm and as an example of disruptive, non-targeted malware that also highlighted industrial control system exposure.

High-confidence behavior and impact described in the content include rapid self-propagation over UDP/1434, widespread Internet congestion and denial-of-service effects, and continued scanning activity observable on the public Internet decades later. The affected platforms explicitly mentioned are Microsoft SQL Server 2000 and MSDE 2000; client systems were not affected. The content also notes that the exploited vulnerability had been patched roughly six months before the outbreak, and that Microsoft stated the MS02-039 patch was effective in protecting SQL Server 2000 and MSDE 2000 against SQL Slammer. No specific threat actor attribution is provided in the content. Known aliases directly mentioned are Sapphire and SQL-Hell.

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MITRE ATT&CK

Techniques & procedures

6 distinct techniques documented for this family, organized by ATT&CK tactic.

Initial Access

1 technique
T1190Exploit Public-Facing ApplicationEvidence2

"SQL Slammer" and "TCP sequence prediction attack" are listed among linked security incident topics; SQL Slammer is historically associated with SQL Server exploitation.

Execution

1 technique
T1203Exploitation for Client ExecutionEvidence1
TacticExecution

By sending a carefully crafted packet to the Resolution Service, an attacker could cause portions of system memory (the heap in one case, the stack in the other) to be overwritten. Overwriting it with carefully selected data could allow the attacker to run code in the security context of the SQL Server service.

Lateral Movement

1 technique
T1210Exploitation of Remote ServicesEvidence1

The SQL Slammer worm that attacked Microsoft SQL and MSDE, which crashed the Internet.

T1572Protocol TunnelingEvidence1

A second kind of covert channel, aimed at subverting firewall–based filtering, uses standard ports for passing non-standard traffic.

Impact

2 techniques
T1498Network Denial of ServiceEvidence1
TacticImpact

A second kind of covert channel, aimed at subverting firewall–based filtering, uses standard ports for passing non-standard traffic. Firewalls that enforce a “block-all-but-necessary” approach to regulating traffic are the typical targets of standard port abuse. A recent (25 Jan 2003) case of standard port abuse involved a Denial of Service (DOS) attack that was variously known as the ‘SQL Slammer’ worm, ‘Sapphire’ and “SQL-Hell’.

T1498.001Direct Network FloodEvidence1
TacticImpact

The infected host starts transmitting 376 byte long UDP packets at a very high rate to random IP addresses on the Internet thereby generating overwhelming traffic.

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Threat actor attribution

Named campaigns wielding this family, with evidence pinned to each claim.

Exploited vulnerabilities

CVEs this family uses for access and lateral movement.

Detection signatures

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MITRE ATT&CK mapping6

Every documented technique, ranked by evidence weight.

Researcher chatter

Reddit, Mastodon, and CTI community discussion around this family.