Chrommme is a backdoor identified by ESET within the Gelsemium cyberespionage ecosystem. It was found during analysis of Gelsemium activity and shared a command-and-control server with Gelsevirine; ESET also reported it on a machine compromised by Gelsemium, linking it to that intrusion set with high confidence. Gelsemium has been active since at least 2014 and has targeted organizations in East Asia and the Middle East, including governments, religious organizations, electronics manufacturers, and universities.
Based on the provided content, Chrommme can collect data from the local system, retrieve the username from a targeted host, capture screenshots, store captured system information locally prior to exfiltration, encrypt and store collected data on disk before exfiltration, and exfiltrate collected data via its C2 channel. It also uses Windows API functionality including WinExec for execution. The content does not provide a specific initial infection vector for Chrommme itself, nor any concrete file paths, mutexes, hashes, or network indicators unique to this malware.
Mallory pivots from this family to the IOCs, detections, and named campaigns that touch your stack, and pages you when something new lands.
1 distinct threat actor attributed by public researchers. Open in Mallory to see the full evidence chain and overlapping campaigns.
Chrommme: Chrommme is a backdoor we found during our adventures in the Gelsemium ecosystem.
18 distinct techniques documented for this family, organized by ATT&CK tactic.
The content repeatedly describes payloads, strings, configuration files, scripts, URLs, and binaries being obfuscated or encoded using Base64, XOR, RC4, AES, RSA, hex encoding, custom algorithms, and other methods across many malware families and threat actors.
The content repeatedly describes malware and threat actors using commands and APIs such as ipconfig /all, ifconfig, arp -a, route print, nbtstat, netsh, GetAdaptersInfo, and GetIpNetTable to gather IP addresses, MAC addresses, DNS, DHCP, gateways, routing tables, ARP cache, proxy settings, domains, and network adapter/interface details.
The content repeatedly describes malware and threat actors collecting usernames, identifying logged-in users, running whoami/query user/quser, checking whether the current user is an administrator, enumerating user sessions, and gathering account details from compromised hosts.
The content is a long ATT&CK-style listing of malware and threat actors that collect host details such as OS version, hostname, architecture, CPU, memory, BIOS, language, and other basic system characteristics; examples include use of commands like systeminfo, ver, uname, sw_vers, and WMI queries.
Multiple entries describe enumerating local, logical, or physical drives and disk/volume information, e.g., 'can enumerate local drives,' 'GetLogicalDrives,' 'fsutil fsinfo drives,' 'list drives,' and 'discover logical drive information including the drive type, free space, and volume information.'
The content repeatedly describes threat actors and malware collecting, stealing, identifying, copying, or staging files, documents, credentials, logs, databases, and other information from compromised hosts or local systems.
The content repeatedly describes adversaries and malware storing collected data, command output, credentials, archives, or files in local temporary folders, working directories, hidden directories, registry locations, recycle bins, or specific files prior to exfiltration.
"Agent Tesla can capture screenshots of the victim’s desktop"; "AppleSeed can take screenshots on a compromised host"; "APT28 has used tools to take screenshots from victims"; "Cobalt Strike's Beacon payload is capable of capturing screenshots"; "PowerSploit's Get-TimedScreenshot Exfiltration module can take screenshots at regular intervals"; "Hydraq includes a component based on the code of VNC that can stream a live feed of the desktop"
"AppleSeed has compressed collected data before exfiltration."; "APT28 used a publicly available tool to gather and compress multiple documents..."; "Aria-body has used ZIP to compress data..."; "Cadelspy...compress stolen data into a .cab file."; "Daserf hides collected data in password-protected .rar archives."; "FIN6 has compressed log files into a ZIP archive prior to staging and exfiltration."; "Lazarus Group has compressed exfiltrated data with RAR...archive specified directories in .zip format"; "XCSSET will compress entire ~/Desktop folders..."
ADVSTORESHELL exfiltrates data over the same channel used for C2... Agrius exfiltrated staged data using tools such as Putty and WinSCP, communicating with command and control servers... numerous malware and groups sent victim data, files, credentials, or host information over existing C2 channels.
14 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
Backdoor found in the broader Gelsemium ecosystem. Although code similarities are limited, shared C&C infrastructure and victim overlap suggest some relationship to the group.
Malware that exfiltrates collected data via its C2 channel.
Information-stealing malware that records system information locally before exfiltration.
Malware that can retrieve the username from a targeted system.
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.