Researchers at Datadog uncovered a new cryptojacking campaign linked to the attackers behind\u00a0Spinning YARN<\/a> campaign.<\/p>\n\n\n\n
\"Image\": \"alpine\",\n\"HostConfig\": {\n \"Binds\": [\"\/:\/mnt\"]\n}<\/code><\/pre>\n\n\n\n
If this step is successful, the attacker gains access to the Docker host’s underlying filesystem through the \/mnt directory inside the container, allowing them to escalate their privileges.<\/p>\n\n\n\n
In addition to defining the container image and host configuration parameters, the attacker executes a shell command within the container itself to set the root of subsequent processes.
<\/gwmw><\/p>\n\n\n\n
The attackers were observed deploying multiple payloads, including
<\/gwmw>a remote access tool ( chkstart<\/code><\/a>) that downloads and executes additional malicious payloads and a tool to perform lateral movement (
exeremo<\/code><\/a>) used to propagate the malware via SSH.<\/p>\n\n\n\n
“After the attacker gains initial access and achieves execution via cron, the next stage of the campaign is to fetch and execute a new shell script\u2014
b.sh<\/code>. This script contains a base64-encoded tar archive of a new binary named\u00a0
vurl<\/code>. The script decodes and extracts this binary to\u00a0\/usr\/bin\/vurl, overwriting the existing shell script version, before fetching and executing one of two shell scripts\u2014
ar.sh<\/code>\u00a0or\u00a0
ai.sh<\/code>.” reads the
report<\/a> published by the researchers.<\/em>
<\/gwmw><\/p>\n\n\n\n
The attackers use an unusual\u00a0persistence mechanism<\/a>\u00a0by modifying existing systemd services and using the\u00a0
ExecStartPost<\/code>\u00a0configuration option to execute malicious commands.<\/p>\n\n\n\n
The script is ultimately used to fetch the next-stage payload “chkstart.”<\/p>\n\n\n\n