F5 BIG-IP APM Malware Injects a PHP Web Shell Into Memory, Evading Disk Scans
Sophos found F5 BIG-IP APM malware that injects a PHP web shell into Apache's memory, evading disk scans, linked to exploited CVE-2025-53521.
Sophos's September 7 analysis describes malware tied to F5's c05d5254 activity that hooks apr_dso_load, modifies the libphp PHP module in memory, and injects a PHP web shell when Apache loads apm_css.php3, full_wt.php3 or webtop_popup_css.php3, leaving on-disk files clean. A separate installer infects /usr/sbin/httpd and umount, runs before Apache starts, disables SELinux (per ESET's related PoisonedRefresh analysis), and opens a local socket at /run/bigtlog.pipe for shell access. The activity is linked to CVE-2025-53521 in BIG-IP APM, rated 9.8 CVSS 3.1, patched in October 2025, added to CISA KEV on March 27, 2026.
Top 10 Best Endpoint Encryption Software in 2026
A 2026 roundup of ten endpoint encryption products argues the engines are solved and buyers should choose management layers like Intune, Sophos, or Trellix.
The guide ranks ten endpoint encryption options, arguing BitLocker and FileVault have won the engine war so the real purchase decision is the management layer for compliance proof, key escrow, and cross-platform policy. Microsoft BitLocker with Intune is named the baseline for Windows estates, with Sophos, ESET, Trend Micro, Check Point, Trellix, and others covering mixed or regulated fleets. It also warns that TrueCrypt-lineage freeware is unmaintained and that Kaspersky cannot be sold to US customers.