In a statement about the breach, the PHP.net team reassured developers that neither the source tarball downloads nor the Git repository were modified or compromised.
The possibility of code depositories being tainted is the worst possible outcome of this kind of breach, so it comes as a relief that nothing that might lead to the distribution of backdoor code has resulted as a consequence of the hack.
SSL access to php.net websites has been temporarily suspended pending the installation of a new SSL certificate. As an additional precaution, user passwords will be reset.
The team behind the php.net site explain their rationale for these actions, and their progress in restoring normal services, in a detailed blog post (extract below).
All affected services have been migrated off those servers. We have verified that our Git repository was not compromised, and it remains in read-only mode as services are brought back up in full.
As it's possible that the attackers may have accessed the private key of the php.net SSL certificate, we have revoked it immediately. We are in the process of getting a new certificate, and expect to restore access to php.net sites that require SSL (including bugs.php.net and wiki.php.net) in the next few hours.
Php.net has promised to produce a full post-mortem on the attack after its team gets through restoring services to normal. Problems with the php.net site were flagged up on Thursday when Google began blocking access to the site after its Safe Browsing technology – used in its Chrome browser, Mozilla's Firefox browser and Apple's Safari browser – detected that that some php.net pages were booby-trapped with links to malicious software.
This meant that surfers visiting the PHP.net site using Google Chrome, for example, were confronted by a warning (screenshot here) firmly instructing them not to proceed any further.
PHP is an open-source web development language used on millions of websites, including those powered by the popular Wordpress and Joomla suites. Hundreds of thousands of developers were potentially exposed to the attack, even though it's likely that only a small percentage were actually pwned.
The hack itself was quite devious and deliberately designed to resemble a false positive.
However, security researchers at Barracuda Networks captured and shared a PCAP (packet capture) file that shows the malicious behaviour.
Subsequent analysis by security tools firm Alien Vault exposed a sophisticated attack, featuring obfuscated content and DNS trickery, ultimately aimed at running drive-by download-style attacks through the Magnitude Exploit Kit. The hack ultimately targeted vulnerable Java or Adobe Acrobat Reader browser plugs in on the machines of visiting surfers.
"Based on that information we have determined that somehow the attackers were able to inject a malicious iFrame into the PHP.net website that was redirecting to an Exploit Kit," a detailed blog post by Alien Vault's Jamie Blasco explains.
As Barracuda notes, if the intention was simply to distribute malware, then hacking into the ad network of a popular site like php.net would have been the more logical and straightforward path to take. The unknown attackers behind the assault have taken the trouble to cook up something far more complex and this naturally leads to the suspicion that we're more likely to be dealing with cyber-espionage of some sort, rather than more conventional profit-motivated malware distribution. ®