Moses Staff Hackers Targeting Israeli Organizations for Cyber Espionage

The politically motivated Moses Staff hacker group has
been observed using a custom multi-component toolset with the goal
of carrying out espionage against its targets as part of a new
campaign that exclusively singles out Israeli organizations.

First publicly documented^[1]
in late 2021, Moses Staff is believed to be sponsored by the
Iranian government, with attacks reported against entities in
Israel, Italy, India, Germany, Chile, Turkey, the U.A.E., and the
U.S.

Earlier this month, the hacker collective was observed
incorporating a previously undocumented remote access trojan (RAT)
called “StrifeWater^[2]” that masquerades as the
Windows Calculator app to evade detection.

“Close examination reveals that the group has been active for
over a year, much earlier than the group’s first official public
exposure, managing to stay under the radar with an extremely low
detection rate,” findings from FortiGuard Labs reveal^[3].

The latest threat activity involves an attack path that
leverages the ProxyShell^[4]
vulnerability in Microsoft Exchange servers as an initial infection
vector to deploy two web shells, followed by exfiltrating Outlook
Data Files (.PST^[5]) from the compromised
server.

Subsequent phases of the infection chain involve an attempt to
steal credentials by dumping the memory contents of a critical
Windows process called Local Security Authority Subsystem Service
(Lsass.exe^[6]), before dropping and
loading the “StrifeWater” backdoor (broker.exe).

The installation of the “Broker” implant, which is used to
execute commands fetched from a remote server, download files, and
exfiltrate data from target networks, is facilitated by a loader
that masquerades as a “Hard Disk Drives Fast Stop Service” dubbed
“DriveGuard” (drvguard.exe).

On top of that, the loader is also responsible for launching a
watchdog mechanism (“lic.dll”) that ensures its own service is
never interrupted by restarting the DriveGuard every time it’s
stopped as well as ensuring that the loader is configured to run
automatically on system startup.

The broker backdoor, for its part, is also equipped to delete
itself from the disk using a CMD command, capture screenshots, and
update the malware to replace the current module on the system with
a file received from the server.

StrifeWater is also notable for its attempts to stay under the
radar by posing as the Windows Calculator app (calc.exe), with
FortiGuard Labs researchers discovering two older samples dating
back to the end of December 2020, suggesting that the campaign has
been operational for over a year.

The attribution to Moses Staff is based on similarities in the web shells^[7] used in previously
disclosed attacks and its pattern of victimology.

“The group is highly motivated, capable, and set on damaging
Israeli entities,” the researchers said. “At this point, they
continue to depend on 1-day exploits for their initial intrusion
phase. Although the attacks we identified were carried out for
espionage purposes, this does not negate the possibility that the
operators will later turn to destructive measures.”