Proxysvc is a Windows malware implant associated with Lazarus Group activity. It has been described as an undocumented implant and has also been characterized as a downloader within Lazarus tooling clusters. The malware performs host reconnaissance by enumerating running processes, searching the local system, collecting network adapter details, identifying domain and username information from active remote sessions, retrieving system time, and querying Windows Registry values to profile the operating system and processor. It automatically gathers victim metadata and transmits the collected information to its control server.
Proxysvc supports data theft and remote tasking through a custom command-and-control protocol. Observed functionality includes exfiltrating collected data over the control channel, deleting attacker-specified files, overwriting files before deletion, and removing itself from disk. It can also establish persistence by registering itself as a Windows service and running as a standalone process. The combination of reconnaissance, service-based persistence, exfiltration, and cleanup behavior is consistent with post-compromise Lazarus tradecraft used to profile victims, maintain access, and reduce forensic visibility.
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1 distinct threat actor attributed by public researchers. Open in Mallory to see the full evidence chain and overlapping campaigns.
Similarly, they have been using the set of software below ... S0238 Proxysvc
21 distinct techniques documented for this family, organized by ATT&CK tactic.
The content repeatedly describes malware and threat actors querying, enumerating, opening, and reading Windows Registry keys and values, e.g., "APT41 queried registry values to determine items such as configured RDP ports and network configurations" and "Reg may be used to gather details from the Windows Registry of a local or remote system at the command-line interface."
AdFind can extract subnet information from Active Directory; actors used ipconfig /all after exploiting a machine; numerous malware and groups used ipconfig, ifconfig, arp, route, netsh, nbtstat, NBTscan, and related APIs to gather IP, MAC, DNS, DHCP, gateway, proxy, domain, ARP cache, routing, and adapter details.
Tasklist can be used to discover processes running on a system. Numerous malware families and threat groups are described as listing running processes, collecting PIDs, checking for specific process names, or enumerating loaded modules.
The content repeatedly describes malware and threat actors collecting host details such as hostname, OS version, architecture, CPU, memory, BIOS, language, and other machine characteristics; e.g., "Action RAT has the ability to collect the hostname, OS version, and OS architecture of an infected host."
The content is a long ATT&CK-style listing of groups and malware that can 'list files and directories,' 'search for files,' 'enumerate drives,' 'gather file metadata,' or 'browse file systems' on compromised hosts.
Numerous entries mention enumerating drives, logical disks, disk type, free space, or volume information; examples include 'Babuk can enumerate disk volumes,' 'Cuba can enumerate local drives,' and 'TAINTEDSCRIBE can use DriveList to retrieve drive information.'
The content repeatedly describes malware and threat actors collecting the current date, time, or time zone from victim systems, including examples such as "The net time command can be used... to determine the local or remote system time" and commands like "net time \\hostname" and "w32tm /tz".
Examples include 'Bazar can also check if the Russian language is installed,' 'DropBook has checked for the presence of Arabic language,' 'Maze has checked the language of the infected system,' and 'SynAck ... checks installed keyboard layouts to estimate if it has been launched from a certain list of countries.'
Andariel has collected large numbers of files from compromised network systems for later extraction... APT28 has retrieved internal documents from machines inside victim environments... BADNEWS crawls the victim's local drives and collects documents... many listed groups and malware collect files, documents, credentials, payment card data, or other information from compromised hosts.
Agrius used a custom tool, sql.net4.exe, to query SQL databases and then identify and extract personally identifiable information... AppleSeed has automatically collected data from USB drives, keystrokes, and screen images before exfiltration... Ember Bear engages in mass collection from compromised systems during intrusions.
This implant incorporated a custom control server protocol that sends traffic over port 443. The implementation does not format the packets in standard SSL, but rather in a custom format and transmitted over SSL—hence, FakeTLS.
The content is a long ATT&CK-style listing showing numerous malware families and threat groups that 'use HTTP,' 'use HTTPS,' 'HTTP POST requests,' 'HTTP GET requests,' or 'HTTP/S' for command and control communications.
9 indicators attributed across vendor reports, sandbox runs, and researcher write-ups. Full values are available in Mallory.
IPs, domains, and DNS infrastructure linked to this family.
File hashes (MD5, SHA-1, SHA-256) from samples and reports.
37 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
... Proxysvc ... (v1.2→v1.3) ...
Proxysvc (v1.2→v1.3)
Collects network adapter and domain/username information from current remote sessions.
Malware that performs data exfiltration over the control server channel using a custom protocol.
Match every observed IP, domain, and hash against your live telemetry.
Named campaigns wielding this family, with evidence pinned to each claim.
CVEs this family uses for access and lateral movement.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Every documented technique, ranked by evidence weight.
Reddit, Mastodon, and CTI community discussion around this family.