Malicious RTF — malware analysis report

Static analysis result for SHA-256 15886aa2b7150dae…

MALICIOUS

RTF

347.6 KB First seen: 2019-08-04
MD5: 3858955ed48ae94c3ed5b6c83aeefd4f SHA-1: 20af54acb2d3755751a037f43d14506af07b4c03 SHA-256: 15886aa2b7150dae599e506f22911e0a0dcc12bb90b575b082027a07a8ce6c0b
220 Risk Score

Malware Insights

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

The file is an RTF document containing embedded OLE object data, specifically triggering heuristics related to Equation Editor exploits and OLE object activation. The critical ClamAV detection confirms this is a known exploit for CVE-2017-11882, which allows for arbitrary code execution. This technique is commonly used to deliver secondary payloads, hence the likely attack pattern.

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_off0000003c.bin rtf-objdata-decoded RTF \objdata at offset 0x3C 112491 bytes
SHA-256: 74618392c1fb5cd3b1445f17e1dfc13786456fd44aef86f468b29da68dfd129b