Companies in Russia and Moldova have been the target of a phishing campaign orchestrated by a little-known cyber espionage group known as XDSpy.
The findings come from cybersecurity firm F.A.C.C.T., which said the infection chains lead to the deployment of a malware called DSDownloader. The activity was observed this month, it added.
XDSpy is a threat actor of indeterminate origin that was first uncovered by the Belarusian Computer Emergency Response Team, CERT.BY, in February 2020. A subsequent analysis by ESET attributed the group to information-stealing attacks aimed at government agencies in Eastern Europe and the Balkans since 2011.
Attack chains mounted by the adversary are known to leverage spear-phishing emails in order to infiltrate their targets with a main malware module known as XDDown that, in turn, drops additional plugins for gathering system information, enumerating C: drive, monitoring external drives, exfiltrating local files, and gathering passwords.
Over the past year, XDSpy has been observed targeting Russian organizations with a C#-base dropper named UTask that’s responsible for downloading a core module in the form of an executable that can fetch more payloads from a command-and-control (C2) server.
The latest set of attacks entails the use of phishing emails with agreement-related lures to propagate a RAR archive file that contains a legitimate executable and a malicious DLL file. The DLL is then executed by means of the former using DLL side-loading techniques.
The library takes care of downloading and running DSDownloader, which, in turn, opens a decoy file as a distraction while surreptitiously downloading the next-stage malware from a remote server. F.A.C.C.T. said the payload was no longer available for download at the time of analysis.
The onset of the Russo-Ukrainian war in 2022 has witnessed a significant escalation in cyber attacks on both sides, with Russian companies compromised by DarkWatchman RAT as well as by activity clusters tracked as Core Werewolf, Hellhounds, PhantomCore, Rare Wolf, ReaverBits, and Sticky Werewolf, among others in recent months.
What’s more, pro-Ukrainian hacktivist groups such as Cyber.Anarchy.Squad has also set its sights on Russian entities, conducting hack-and-leak operations and disruptive attacks against Infotel and Avanpost.
The development comes as the Computer Emergency Response Team of Ukraine (CERT-UA) warned of a spike in phishing attacks carried out by a Belarusian threat actor called UAC-0057 (aka GhostWriter and UNC1151) that distribute a malware family referred to as PicassoLoader with an aim to drop a Cobalt Strike Beacon on infected hosts.
It also follows the discovery of a new campaign from the Russia-linked Turla group that utilizes a malicious Windows shortcut (LNK) file as a conduit to serve a fileless backdoor that can execute PowerShell scripts received from a legitimate-but-compromised server and disable security features.
“It also employs memory patching, bypass AMSI and disable system’s event logging features to impair system’s defense to enhance its evasion capability,” G DATA researchers said. “It leverages Microsoft’s msbuild.exe to implement AWL (Application Whitelist) Bypass to avoid detection.”