Auto-generated rule - file iam-alt.exe

Hunt Hypothesis

This detection identifies the execution of a suspicious binary named iam-alt.exe, which likely represents an adversary establishing persistence or executing initial reconnaissance tools within the Azure environment. Proactive hunting for this artifact is essential to validate its legitimacy against known good baselines and prevent potential lateral movement or credential theft before it escalates into a broader compromise.

YARA Rule

rule iam_alt_iam_alt : Toolkit  {
	meta:
		description = "Auto-generated rule - file iam-alt.exe"
		author = "Florian Roth"
		reference = "http://www.coresecurity.com/corelabs-research/open-source-tools/pass-hash-toolkit"
		date = "2015-07-10"
		score = 80
		hash = "2ea662ef58142d9e340553ce50d95c1b7a405672acdfd476403a565bdd0cfb90"
	strings:
		$s0 = "<cmd>. Create a new logon session and run a command with the specified credentials (e.g.: -r cmd.exe)" fullword ascii /* PEStudio Blacklist: strings */ /* score: '59.00' */
		$s1 = "IAM-ALT v1.1 - by Hernan Ochoa ([email protected], [email protected]) - (c) 2007-2008 Core Security Technologies" fullword ascii /* PEStudio Blacklist: strings */ /* score: '43.00' */
		$s2 = "This tool allows you to change the NTLM credentials of the current logon session" fullword ascii /* PEStudio Blacklist: strings */ /* score: '31.00' */
		$s3 = "username:domainname:lmhash:nthash" fullword ascii /* PEStudio Blacklist: strings */ /* score: '15.00' */
		$s4 = "Error in cmdline!. Bye!." fullword ascii /* score: '12.00' */
		$s5 = "Error: Cannot open LSASS.EXE!." fullword ascii /* score: '12.00' */
		$s6 = "nthash is too long!." fullword ascii /* score: '8.00' */
		$s7 = "LSASS HANDLE: %x" fullword ascii /* score: '5.00' */
	condition:
		uint16(0) == 0x5a4d and filesize < 240KB and 2 of them
}

Deployment Notes

This YARA rule can be deployed in the following contexts:

Microsoft Defender for Endpoint — Custom indicators / advanced hunting
Email Gateway — Attachment scanning
File Share Monitoring — Periodic scanning of shared drives
YARA CLI — Manual threat hunting on endpoints

This rule contains 8 string patterns in its detection logic.

References

False Positive Guidance

Here are 4 specific false positive scenarios for the iam-alt.exe detection rule in an enterprise environment, along with suggested filters and exclusions:

Scheduled Identity Management Health Checks
- Scenario: The enterprise utilizes a custom internal tool named iam-alt.exe (Identity Access Manager - Alternative) to run nightly health checks on Active Directory replication status and certificate expiration. This process executes automatically via Windows Task Scheduler at 02:00 AM, generating file system events that mimic suspicious activity.
- Filter/Exclusion: Create an exclusion rule based on the Process Parent Name (TaskScheduler.exe) combined with a specific User Account (e.g., svc-iam-healthcheck). Alternatively, filter by the File Path if the tool runs from a dedicated system directory like C:\Program Files\InternalTools\IAM\.
Endpoint Detection and Response (EDR) Agent Updates
- Scenario: The organization’s EDR solution (e.g., CrowdStrike or SentinelOne) deploys a lightweight auxiliary agent named iam-alt.exe to handle real-time identity policy enforcement. When the EDR management server pushes a configuration update or signature refresh, this executable is instantiated by the main EDR service (ccSetMgr.exe or SentinelAgentService) on all endpoints.
- Filter/Exclusion: Exclude events where the Parent Process Name matches known EDR services (e.g., ccSetMgr.exe, SentinelAgentService.exe) and the Hash Algorithm (SHA256) of iam-alt.exe matches a whitelisted baseline hash stored in your SIEM.
IT Admin Manual Remediation Scripts
- Scenario: During quarterly audit cycles, Identity Administrators manually launch iam-alt.exe from their local desktops to perform bulk user attribute corrections or