Description
NetSarang Xmanager Enterprise 5.0 Build 1232, Xmanager 5.0 Build 1045, Xshell 5.0 Build 1322, Xftp 5.0 Build 1218, and Xlpd 5.0 Build 1220 contain a malicious nssock2.dll that implements a multi-stage, DNS-based backdoor. The dormant library contacts a C2 DNS server via a specially crafted TXT record for a month‑generated domain. After receiving a decryption key, it then downloads and executes arbitrary code, creates an encrypted virtual file system (VFS) in the registry, and grants the attacker full remote code execution, data exfiltration, and persistence. NetSarang released builds for each product line that remediated the compromise: Xmanager Enterprise Build 1236, Xmanager Build 1049, Xshell Build 1326, Xftp Build 1222, and Xlpd Build 1224. Kaspersky Lab identified an instance of exploitation in the wild in August 2017.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
NetSarang Computer, Inc. Xmanager Enterprise
Default version status: unaffected
5.0 Build 1232affected
NetSarang Computer, Inc. Xmanager
Default version status: unaffected
5.0 Build 1045affected
NetSarang Computer, Inc. Xshell
Default version status: unaffected
5.0 Build 1322affected
NetSarang Computer, Inc. Xftp
Default version status: unaffected
5.0 Build 1218affected
NetSarang Computer, Inc. Xlpd
Default version status: unaffected
5.0 Build 1220affected
References
- https://web.archive.org/web/20181022035109/https://www.netsarang.com/news/security_exploit_in_july_18_2017_build.html ↗
- https://usa.kaspersky.com/about/press-releases/shadowpad-attackers-hid-backdoor-in-software-used-by-hundreds-of-large-companies-worldwide ↗
- https://securelist.com/shadowpad-in-corporate-networks/81432/ ↗
- https://www.vulncheck.com/advisories/netsarang-malicious-backdoor-supply-chain-compromise ↗