Malicious RTF — malware analysis report

Static analysis result for SHA-256 e7df264e4d3baa93…

MALICIOUS

RTF

14.3 KB First seen: 2019-05-16
MD5: 2b4bb8fc2d9d7469b30b457a9fb07d7e SHA-1: 49ebf2e3e091ef0ff66fd7651bfd1cd0571d67dc SHA-256: e7df264e4d3baa936cbeba89833aee4c67e3d9557f06bb2162ec6e2b443df653
220 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample is an RTF document containing OLE object data and specifically triggers heuristics related to the Equation Editor vulnerability (CVE-2017-11882). This vulnerability is known to allow for arbitrary code execution. The ClamAV detection name further confirms this exploit. The attack pattern is consistent with a malicious attachment delivered via spearphishing, aiming to exploit this known vulnerability to gain initial execution.

Heuristics 5

  • Equation Editor CLSID critical CVE likely RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • Ole10Native stream in RTF OLE object high CVE related RTF_OLE10NATIVE_STREAM
    RTF contains an embedded OLE object with an Ole10Native stream. This is a strong payload-container signal and is related to Word/OLE exploit delivery, but it is not specific enough on its own to assign a CVE.
  • ClamAV: Rtf.Exploit.CVE_2017_11882-6584355-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Rtf.Exploit.CVE_2017_11882-6584355-1
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000014bb.bin rtf-objdata-decoded RTF \objdata at offset 0x14BB 4654 bytes
SHA-256: 1fd6dffdc90f31b4e41cffb34e238c72b72096dabd00ca11e5f1178bef7789c4