Invalid Code Signature

T1036.001

Sub-technique of T1036 Masquerading.View on attack.mitre.org

About this technique

Adversaries may attempt to mimic features of valid code signatures to increase the chance of deceiving a user, analyst, or tool. Code signing provides a level of authenticity on a binary from the developer and a guarantee that the binary has not been tampered with. Adversaries can copy the metadata and signature information from a signed program, then use it as a template for an unsigned program. Files with invalid code signatures will fail digital signature validation checks, but they may appear more legitimate to users and security tools may improperly handle these files.

Unlike Code Signing, this activity will not result in a valid signature.

Detection rules0

Rules on DetectionCode tagged with T1036.001.

Sigma0

No Sigma rules are mapped to this technique yet.

Splunk0

No Splunk rules are mapped to this technique yet.

Groups2

Software7

Campaigns0

None recorded.

Procedure examples9

Groups2

Used byProcedure example
GroupAPT37

APT37 has signed its malware with an invalid digital certificates listed as “Tencent Technology (Shenzhen) Company Limited.”

GroupWindshift

Windshift has used revoked certificates to sign malware.

Software7

Used byProcedure example
MalwareBADNEWS

BADNEWS is sometimes signed with an invalid Authenticode certificate in an apparent effort to make it look more legitimate.

MalwareGelsemium

Gelsemium has used unverified signatures on malicious DLLs.

MalwareNETWIRE

The NETWIRE client has been signed by fake and invalid digital certificates.

ToolPcShare

PcShare has used an invalid certificate in attempt to appear legitimate.

MalwareRegin

Regin stage 1 modules for 64-bit systems have been found to be signed with fake certificates masquerading as originating from Microsoft Corporation and Broadcom Corporation.

MalwareSplatCloak

SplatCloak has used a revoked certificate to exploit Windows driver execution policy where certificates issued before a specific date could still load.

MalwareWindTail

WindTail has been incompletely signed with revoked certificates.

References1

  1. Threatexpress MetaTwin 2017 Open source
    Vest, J. (2017, October 9). Borrowing Microsoft MetaData and Signatures to Hide Binary Payloads. Retrieved September 10, 2019.

Data from MITRE ATT&CK® (Enterprise). ATT&CK® is a registered trademark of The MITRE Corporation.