Severity
Medium
Analysis Summary
Cisco Talos recently observed attackers changing the file formats they use in an attempt to thwart common antivirus engines. This can happen across other file formats, but today, we are showing a change of approach for an actor who has deemed antivirus engines perhaps “too good” at detecting macro-based infection vectors. We’ve noticed that the OpenDocument (ODT) file format for some Office applications can be used to bypass these detections. ODT is a ZIP archive with XML-based files used by Microsoft Office, as well as the comparable Apache OpenOffice and LibreOffice software.
Impact
Exposure of sensitive information
Indicator of Compromise
Malware Hash SH256
- 02000ddf92ceb363760acc1d06b7cd1f05be7a1ca6df68586e77cf65f4c6963e
- 19027327329e2314b506d9f44b6871f2613b8bb72aa831004e6be873bdb1175d
- 20919e87d52b1609bc35d939695405212b8ca540e50ce8bece01a9fccfa70169
- 2f4aa28974486152092669c85d75232098d32446adefeeef3a94ad4c58af0fc8
- 429d270195bed378495349cf066aee649fd1c8c450530d896844b1692ddddc77
- 80c62c646cce264c08deb02753f619da82b27d9c727e854904b9b7d88e45bf9e
- 84cb192cc6416b20293dfb8c621267e1584815a188b67757fa0d1af29a7cfdcd
- b2b51864fa2f80f8edbdaf6721a6780e15a30291a748c2dfc52d574de0d8c3ed
- d099eac776eabf48f55a75eb863ad539a546202da02720aa83d88308be3ce4ca
- de8e85328b1911084455e7dc78b18fd1c6f84366a23eaa273be7fbe4488613dd
- efb81fb8095319f5ee6fd4d6741b80386a824b9df05460d16d22cad1d6bbb35d
- f24c6a56273163595197c68abeab7f18e4e2bedd6213892d83cdb7a191ff9900
- f5194cc197d98ed9078cceca223e294c5ec873b86cbeff92eb9eaca17fc90584
- f9138756639104e2c392b085cc5a98b1db77f0ed6e3b79eacac9899001ed7116
Remediation
- Block all threat indicators at your respective controls.
- Always be suspicious about emails sent by unknown senders.
- Never click on the links/attachments sent by unknown senders.