BLUELIGHT
BLUELIGHT is a backdoor/reconnaissance malware associated with the North Korea-linked APT37/ScarCruft/Vedalia espionage group. Reporting describes it as a second-stage payload and, in some campaigns, as part of a multistage intrusion chain including watering-hole attacks and Internet Explorer exploitation against South Korean targets, including a South Korean online newspaper. It has also been observed in later ScarCruft activity such as the Ruby Jumper campaign, where it was distributed alongside other tooling.
Its command-and-control tradecraft relies on legitimate cloud services and multiple cloud providers; reporting specifically notes use of Microsoft OneDrive via the Graph API, and later reporting cites Google Drive, OneDrive, pCloud, and BackBlaze. BLUELIGHT can exfiltrate data over its C2 channel and can zip files before exfiltration. Documented collection capabilities include enumerating files and associated metadata, collecting local time, harvesting passwords from Internet Explorer, Edge, Chrome, and Naver Whale, harvesting cookies from Internet Explorer, Edge, Chrome, and Naver Whale, and capturing screenshots on a schedule (every 30 seconds for the first 5 minutes after initiating a C2 loop, then every 5 minutes). It also supports self-uninstallation.
Multiple sources characterize BLUELIGHT as a basic reconnaissance tool or backdoor used by APT37, with one report stating it was used to launch Dolphin’s Python loader on compromised systems and had a more limited role in espionage operations than Dolphin. Stairwell assessed Goldbackdoor as a successor to BLUELIGHT. High-confidence associations in the provided content tie BLUELIGHT to APT37/ScarCruft campaigns targeting South Korean and journalist-related victims, and to cloud-based C2 and browser credential theft activity.
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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
24 distinct techniques documented for this family, organized by ATT&CK tactic.
Initial Access
2 techniquesThe 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.
The malware is distributed through a phishing attack... The phishing emails originated from the account of the former director of South Korea’s National Intelligence Service (NIS), who APT37 previously compromised.
Execution
3 techniquesMITRE ATT&CK techniques... ScarCruft used malicious JavaScript for a watering-hole attack.
"GoGra ... uses the Microsoft Graph API to interact with a command-and-control (C&C) server hosted on Microsoft mail services..."; "Grager ... used the Graph API to communicate with a C&C server hosted on Microsoft OneDrive"; "Onedrivetools ... authenticates to Microsoft Graph API and downloads the second stage payload from OneDrive... fetching the new commands to execute from a file called cmd"
MITRE ATT&CK techniques... ScarCruft exploits CVE-2020-1380 to compromise victims.
Privilege Escalation
1 techniqueStealth
4 techniquesThe 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.
The Python loader includes a script and shellcode, launching a multi-step XOR-decryption, process creation, etc., eventually resulting in the execution of the Dolphin payload in a newly created memory process.
The content repeatedly describes threat actors and malware deleting files, tools, scripts, logs, droppers, staged data, and artifacts from compromised systems to cover tracks, remove evidence, or self-delete.
Credential Access
2 techniques"...used custom malware to steal login and cookie data from common browsers..."; "...extracts the web session cookie and sends it to the C2 server..."; "...stole Chrome browser cookies by copying the Chrome profile directories..."
The content repeatedly describes threat actors and malware stealing usernames, passwords, cookies, session tokens, and other saved credentials from web browsers such as Chrome, Firefox, Internet Explorer, Edge, Opera, Safari, and Yandex.
Discovery
7 techniquesThe content repeatedly describes actors and malware using commands and APIs such as ipconfig /all, ifconfig, arp -a, route print, netsh interface show, GetAdaptersInfo, and GetIpNetTable to gather IP addresses, MAC addresses, DNS, DHCP, gateways, routing tables, ARP cache, proxy settings, 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 admin status, and enumerating user sessions.
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."
"...has a command to retrieve metadata for files on disk as well as a command to list the current working directory." / "...can list files and directories." / "...used the following commands... to obtain information about files and directories: dir c:\ >> %temp%\download ..."
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"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 techniquesAn increasing number of threats have begun to leverage the Microsoft Graph API, usually to facilitate communications with command-and-control (C&C) infrastructure hosted on Microsoft cloud services.
The content repeatedly describes threat actors, malware, and campaigns using HTTP and/or HTTPS for command and control, including examples such as BlackEnergy communicating with C2 over HTTP POST requests and many other families using HTTP/S for C2.
The adversaries had communicated to both Dropbox and Pastebin. APT28 has used Google Drive for C2. APT37 leverages social networking sites and cloud platforms (AOL, Twitter, Yandex, Mediafire, pCloud, Dropbox, and Box) for C2.
Exfiltration
1 techniqueADVSTORESHELL 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
38 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.