I finally sorted out my lab and successful got Cerber infection which encrypted everything with a .ba89 extension. Interestingly this Cerber did not send the standard HTTP request you would expect from Cerber. I did see a lot of Nbstat responses however from several of the IP addresses that sent data over UDP port 6892. I’m presuming these responses is what has allowed Cerber proceed with encryption.
- A few articles on Rig exploit kit and it’s evolution:
- Article on the PseudoDarkleech campaign and its history:
- 300117-rigcerber -> Contains pcapng and payload in password protected zip.
- 126.96.36.199 – sewellwilson.co[.]nz – COMPROMISED WEBSITE
- 188.8.131.52 – guv.mobilevcilhayvan[.]com – RIG-V
- 184.108.40.206 -> 220.127.116.11 UDP port 6892 – Cerber Check In IP Range
- 18.104.22.168 -> 22.214.171.124 – UDP port 6892 – Cerber Check In IP Range
- 126.96.36.199 -> 188.8.131.52 – UDP port 6892 – Cerber Check In IP Range
- 184.108.40.206 -> 220.127.116.11 – UDP port 6892 – Cerber Check In IP Range
- 18.104.22.168 -> 22.214.171.124 – UDP port 6892 – Cerber Check In IP Range
- 126.96.36.199 -> 188.8.131.52 – UDP port 6892 – Cerber Check In IP Range
- Payload was rad14017.tmp.exe -> VirusTotal
- I also put it into HybridAnalysis which failed to deliver Cerber indicating that Cerber might be able to detect a sand boxed environment.
- Created several additional files.
Details of infection chain:
- Compromised site redirects to Rig-V EK via PseudoDarkleech iframe.
- guv.mobilevcilhayvan[.]com is Rig EK, from top to bottom -> Pre-Landing -> Landing Page -> Flash -> Payload
- UDP traffic port 6892 all contained the data”9d5b5326527fd5“
- Dropped payload “rad14017.tmp.exe “.
SHA256: f62b4a1a3dbe7b0cf7e4b1fe55255d74655b96e5d143925d108be1f63f429df1 File name: rad14017.tmp.exe Detection ratio: 8 / 56
- Payload encrypted files with a “.ba89” extension.
- I did not see the usual HTTP request of Cerber. It is likely the Nbstat responses are giving Cerber the go ahead.
- Emerging Threat signatures for Cerber and NBTStat query response.
- Even though I see the Conficker emerging threat signature I can now safely rule this out.
- Cerber changes the background and loads a HTA file containing instructions on how to decrypt your files. It also plays an eerie audio stating that your files have been encrypted in the Windows 7 female USA voice.