SIGNATURE_BASE_EXPL_LOG_CVE_2021_26858_Exchange_Forensic_Artefacts_Mar21_1

rule SIGNATURE_BASE_EXPL_LOG_CVE_2021_26858_Exchange_Forensic_Artefacts_Mar21_1 : LOG CVE_2021_26858
{
	meta:
		description = "Detects forensic artefacts found in HAFNIUM intrusions exploiting CVE-2021-26858"
		author = "Florian Roth (Nextron Systems)"
		id = "f6fa90c7-c2c0-56db-bf7b-dc146761a995"
		date = "2021-03-02"
		modified = "2021-03-04"
		reference = "https://www.volexity.com/blog/2021/03/02/active-exploitation-of-microsoft-exchange-zero-day-vulnerabilities/"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/apt_hafnium_log_sigs.yar#L15-L28"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		logic_hash = "0a8296b7e990e52330412288e9ff71e08a5258fc63c4754e6d0e6d64302f55e6"
		score = 65
		quality = 85
		tags = "LOG, CVE-2021-26858"

	strings:
		$xr1 = /POST (\/owa\/auth\/Current\/themes\/resources\/logon\.css|\/owa\/auth\/Current\/themes\/resources\/owafont_ja\.css|\/owa\/auth\/Current\/themes\/resources\/lgnbotl\.gif|\/owa\/auth\/Current\/themes\/resources\/owafont_ko\.css|\/owa\/auth\/Current\/themes\/resources\/SegoeUI-SemiBold\.eot|\/owa\/auth\/Current\/themes\/resources\/SegoeUI-SemiLight\.ttf|\/owa\/auth\/Current\/themes\/resources\/lgnbotl\.gif)/

	condition:
		$xr1
}