New BendyBear APT malware gets linked to Chinese hacking group


Level 76
Content Creator
Malware Hunter
Aug 17, 2014
Unit 42 researchers today have shared info on a new polymorphic and "highly sophisticated" malware dubbed BendyBear, linked to a hacking group with known ties to the Chinese government.
BendyBear is also "one of the most sophisticated, well-engineered and difficult-to-detect samples of shellcode employed by an Advanced Persistent Threat (APT)" according to a Unit 42 report published earlier today. [...]
Among BendyBear's long list of features and capabilities, Unit 42 says that it:
  • Transmits payloads in modified RC4-encrypted chunks. This hardens the encryption of the network communication, as a single RC4 key will not decrypt the entire payload.
  • Attempts to remain hidden from cybersecurity analysis by explicitly checking its environment for signs of debugging.
  • Leverages existing Windows registry key that is enabled by default in Windows 10 to store configuration data.
  • Clears the host’s DNS cache every time it attempts to connect to its C2 server, thereby requiring that the host resolve the current IP address for the malicious C2 domain each time.
  • Generates unique session keys for each connection to the C2 server.
  • Obscures its connection protocol by connecting to the C2 server over a common port (443), thereby blending in with normal SSL network traffic.
  • Employs polymorphic code, changing its runtime footprint during code execution to thwart memory analysis and evade signaturing.
  • Encrypts or decrypts function blocks (code blocks) during runtime, as needed, to evade detection.
  • Uses position independent code (PIC) to throw off static analysis tools.