Malware

PS1

PS1 is a custom malware associated with the CostaRicto intrusion set. Available reporting indicates it uses a PowerShell-based loader, decrypts components with an XOR key, and injects a payload DLL into memory for execution. These behaviors indicate an emphasis on in-memory execution and evasion through staged loading rather than straightforward on-disk execution. PS1 has been identified alongside other CostaRicto malware, including CostaBricks and SombRAT, as part of that actor’s bespoke toolset. High-confidence public detail on its full functionality, targeting scope, and downstream objectives remains limited.

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MITRE ATT&CK

Techniques & procedures

7 distinct techniques documented for this family, organized by ATT&CK tactic.

Execution

1 technique

T1059.001PowerShellEvidence8

AppleSeed has the ability to execute its payload via PowerShell... APT19 used PowerShell commands to execute payloads... APT28 downloads and executes PowerShell scripts and performs PowerShell commands... Start-Process / Invoke-Command / System.Management.Automation

Privilege Escalation

2 techniques

T1055Process InjectionEvidence1

Aria-body has the ability to inject itself into another process such as rundll32.exe and dllhost.exe... BlackEnergy injects its DLL component into svchost.exe... ComRAT has injected its orchestrator DLL into explorer.exe... Stuxnet injects an entire DLL into an existing, newly created, or preselected trusted process.

T1055.001Dynamic-link Library InjectionEvidence1

Stealth

5 techniques

T1027Obfuscated Files or InformationEvidence5

The content repeatedly describes payloads, strings, configuration files, scripts, URLs, and binaries being obfuscated or encoded using Base64, XOR, RC4, AES, RSA, hex encoding, custom algorithms, and other methods across many malware families and threat actors.

T1027.013Encrypted/Encoded FileEvidence2

Examples throughout the content include 'encrypted payloads decrypted and executed in memory,' 'encrypts its configuration file,' 'AES-encrypted resource,' 'RC4 encrypted embedded scripts,' and 'payload includes an encrypted main component.'

T1055Process InjectionEvidence1

T1055.001Dynamic-link Library InjectionEvidence1

T1140Deobfuscate/Decode Files or InformationEvidence6

The content is a long ATT&CK-style listing of malware and threat groups that 'decrypt', 'decode', 'deobfuscate', 'unpack', or 'decompress' payloads, strings, configuration data, shellcode, and files prior to execution or use.

Command and Control

1 technique

T1105Ingress Tool TransferEvidence1

ACTIVITY FEED

Recent activity

11 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

11 SOURCESView more in app

mitre attack websiteNews

Apr 25, 2022

Command and Scripting Interpreter: PowerShell, Sub-technique T1059.001 - Enterprise | MITRE ATT&CK®

Malware that can use a PowerShell loader.

mitre attack websiteNews

Oct 21, 2021

Updates - Updates - October 2021 | MITRE ATT&CK®

Enterprise New Software: ... PS1

mitre attack websiteNews

Oct 21, 2021

Deobfuscate/Decode Files or Information, Technique T1140 - Enterprise | MITRE ATT&CK®

Malware that uses an XOR key to decrypt a PowerShell loader and payload binary.

mitre attack websiteNews

Oct 21, 2021

Process Injection: Dynamic-link Library Injection, Sub-technique T1055.001 - Enterprise | MITRE ATT&CK®

Malware that injects its payload DLL into memory.

+7 more in the timeline

What this page doesn’t show

The version that knows your environment.

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IOC matching

Match every observed IP, domain, and hash against your live telemetry.

Threat actor attribution

Named campaigns wielding this family, with evidence pinned to each claim.

Exploited vulnerabilities

CVEs this family uses for access and lateral movement.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

MITRE ATT&CK mapping7

Every documented technique, ranked by evidence weight.

Researcher chatter

Reddit, Mastodon, and CTI community discussion around this family.

PS1