Malicious RTF — malware analysis report

Static analysis result for SHA-256 99f9d40ebe5e4493…

MALICIOUS

RTF

13.3 KB First seen: 2019-04-17
MD5: 49f8f37e803f490d9d1adcf0638ab78c SHA-1: da42be72a2c27cdb7645109d8a973d25daccd902 SHA-256: 99f9d40ebe5e4493c7c9414e04d23b1012f79915d14a671c36af71ea373c0f44
220 Risk Score

Malware Insights

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

The file is an RTF document containing an embedded OLE object that triggers the Equation Editor vulnerability (CVE-2017-11882). This vulnerability allows for arbitrary code execution, which is commonly used to download and execute further malicious stages. The ClamAV detection name directly indicates the exploit used.

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_off000014bd.bin rtf-objdata-decoded RTF \objdata at offset 0x14BD 4140 bytes
SHA-256: d60f082050b2ace0f57597949c7fba9c2c6b8ae43683b0b184a27bdb36690bde