BLUELIGHT
BLUELIGHT is a backdoor and basic reconnaissance/second-stage malware associated with the North Korea-linked APT37 threat actor, also known as ScarCruft, Reaper, Ricochet Chollima, and Vedalia. It has been described as a second-stage payload and was used in multistage intrusion chains, including a 2021 watering-hole attack against a South Korean online newspaper that involved an Internet Explorer exploit. In later reporting, BLUELIGHT was also observed in APT37’s 2025 Ruby Jumper campaign, where it was distributed alongside other tooling targeting air-gapped environments.
BLUELIGHT uses legitimate cloud services and multiple cloud providers for command-and-control, including Microsoft OneDrive/Graph API, Google Drive, pCloud, and BackBlaze. Reporting notes it was one of the earliest known malware families to use Microsoft Graph API/OneDrive for C2. It can exfiltrate data over its C2 channel and zip files before exfiltration.
Observed capabilities include collecting the username and local time from a compromised host, enumerating files and associated metadata, harvesting passwords stored in Internet Explorer, Edge, Chrome, and Naver Whale, harvesting cookies from Internet Explorer, Edge, Chrome, and Naver Whale, capturing screenshots every 30 seconds for the first five minutes after initiating a C2 loop and then every five minutes thereafter, and uninstalling itself. Additional reporting states BLUELIGHT can support command execution, file system enumeration, payload download and upload, and self-removal.
BLUELIGHT has also been used operationally to launch the Python loader for the more capable Dolphin backdoor on compromised systems, indicating a supporting role in APT37 espionage operations. Stairwell assessed Goldbackdoor as a successor to BLUELIGHT.
Hunt this family in your stack
Mallory pivots from this family to the IOCs, detections, and named campaigns that touch your stack, and pages you when something new lands.
Vulnerabilities exploited
1 CVE Mallory has correlated with this family across public research and vendor advisories. Each row links to the full Mallory page for that vulnerability.
The backdoor was used as the final payload of a multistage attack in early 2021, involving a watering-hole attack on a South Korean online newspaper, an Internet Explorer exploit, and another ScarCruft backdoor, named BLUELIGHT. | ScarCruft exploits CVE-2020-1380 to compromise victims.
Groups observed using it
4 distinct threat actors attributed by public researchers. Open in Mallory to see the full evidence chain and overlapping campaigns.
Stairwell found a new malware sample named “Goldbackdoor,” which was assessed as a successor of “Bluelight.”
The first known usage was by the North Korea-linked Vedalia espionage group (aka APT37), which developed Bluelight, a second-stage payload that could communicate with several different cloud services for C&C purposes.
BLUELIGHT can harvest cookies from Internet Explorer, Edge, Chrome, and Naver Whale browsers.
...and finally to BLUELIGHT and FOOTWINE for full surveillance.
Techniques & procedures
21 distinct techniques documented for this family, organized by ATT&CK tactic.
Initial Access
2 techniques
Initial Access
Execution
2 techniques
Execution
Privilege Escalation
1 technique
Privilege Escalation
Stealth
3 techniques
Stealth
The content repeatedly describes adversaries using Base64, XOR, RC4, AES, hexadecimal encoding, string encryption, code flattening, custom crypters, and other obfuscation methods to hide payloads, strings, configuration data, URLs, and scripts.
Credential Access
2 techniques
Credential Access
Discovery
6 techniques
Discovery
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 repeatedly describes malware and threat actors obtaining lists of running processes, using utilities such as tasklist, ps, WMI, Get-Process, CreateToolhelp32Snapshot, EnumProcesses, and similar APIs/commands to enumerate active processes on victim systems.
The content repeatedly describes malware and threat actors collecting host details such as OS version, hostname, architecture, CPU, memory, BIOS, domain, language, and other configuration data; e.g., "APT41 uses multiple built-in commands such as systeminfo and net config Workstation to enumerate victim system basic configuration information."
The content repeatedly describes malware and threat actors listing files and directories, enumerating drives, searching for files by extension/name/path, retrieving file metadata, and browsing file systems (for example: "APT28 has used Forfiles to locate PDF, Excel, and Word documents during collection" and "cmd can be used to find files and directories with native functionality such as dir commands").
Multiple malware and threat groups are described as collecting/deriving local system time, date, timestamp, tick count, or time zone (e.g., "used time /t and net time \ip/hostname for system time discovery"; "collects the timestamp from the victim’s machine"; "can collect the time zone information from the system").
Collection
2 techniques
Collection
"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..."
Command and Control
3 techniques
Command and Control
Several entries describe broader use of HTTP/HTTPS and related web mechanisms for C2, including "Crutch has conducted C2 communications with a Dropbox account using the HTTP API," "BLUELIGHT can use HTTP/S for C2 using the Microsoft Graph API," and "Small Sieve can contact actor-controlled C2 servers by using the Telegram API over HTTPS."
Exfiltration
1 technique
Exfiltration
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.
IOCs tracked for this family
1 indicator attributed across vendor reports, sandbox runs, and researcher write-ups. Full values are available in Mallory.
File hashes (MD5, SHA-1, SHA-256) from samples and reports.
Recent activity
39 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
Previously attributed backdoor that uses legitimate cloud services (Google Drive, OneDrive) as part of its operations (e.g., for C2 or data exchange).
Cloud-C2 backdoor that abuses legitimate cloud storage providers (e.g., Google Drive, Microsoft OneDrive, pCloud, BackBlaze) to execute commands, enumerate files, transfer payloads/files, and self-remove.
A late-stage surveillance component used alongside FOOTWINE to enable monitoring of compromised systems (details not further described in the content).
Full-featured backdoor previously associated with APT37 and observed as part of the RubyJumper campaign; used as an attribution indicator in the reporting.
The version that knows your environment.
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.