Sunday, June 11, 2017

SambaCry is reality, crooks are abusing CVE-2017-7494 to spread miners

SambaCry allows a remote hacker to take full control of a vulnerable Linux and Unix system.
nt pipe support = no
to their Samba configuration file and restarting the network’s SMB daemon.
The change will limit clients from accessing some network computers.
The Samba bug appears to be a network wormable issue that could be exploited by a malicious code to self-replicate from vulnerable machine to vulnerable machine without requiring user interaction.
When SambaCry was discovered, nearly 485,000 Samba-enabled computers were found to be exposed on the Internet.
Security researcher speculated that a rapid increase in the number of cyber attacks leveraging the SambaCry issue, just like WannaCry attacks.
Researchers at Kaspersky Lab set up honeypots to detect SambaCry attacks in the wild. The experts have spotted a malware campaign that is exploiting SambaCry vulnerability to infect Linux systems and install a cryptocurrency miner.
“On May 30th our honeypots captured the first attack to make use of this particular vulnerability, but the payload in this exploit had nothing in common with the Trojan-Crypt that was EternalBlue and WannaCry. Surprisingly, it was a cryptocurrency mining utility!” reported Kaspersky.
The independent security researcher Omri Ben Bassat‏ also observed the same campaign that he dubbed “EternalMiner.” The expert confirmed threat actors started exploiting the SambaCry flaw just a week after its discovery to hijack Linux PCs and to install an upgraded version of “CPUminer,” a Monero miner.
Once compromised a Linux Machine exploiting the SambaCry vulnerability, attackers execute two different payloads on the targeted systems:
  • INAebsGB.so — A simple reverse shell that allows a remote attacker to access the target system.
  • cblRWuoCc.so — A backdoor that includes cryptocurrency mining utilities – CPUminer.
“the attacked machine turns into a workhorse on a large farm, mining crypto-currency for the attackers. In addition, through the reverse-shell left in the system, the attackers can change the configuration of a miner already running or infect the victim’s computer with other types of malware” Kaspersky researchers say.
According to Kaspersky, threat actors behind this campaign have already earned 98 XMR, which worth USD 5,380 today. The experts believe that crooks could earn much more with the increase in the number of compromised Linux systems.

“The mining utility is downloaded from the domain registered on April 29th 2017. According to the log of the transactions, the attackers received their first crypto-coins on the very next day, on April 30th. During the first day they gained about 1 XMR (about $55 according to the currency exchange rate for 08.06.2017), but during the last week they gained about 5 XMR per day. This means that the botnet of devices working for the profit of the attackers is growing.,” the researchers say.

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