Malicious RTF — malware analysis report

Static analysis result for SHA-256 7a1568bf2f21a8fc…

MALICIOUS

RTF

120.3 KB First seen: 2019-01-12
MD5: c2f42eb1f3aa9fd612cbe899d801ac2a SHA-1: ef61a73c2f2e34349806aaa63870dcd361c30119 SHA-256: 7a1568bf2f21a8fc3567036b53d3df09226c43599422777d8ee5dd46bf15f9db
220 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor vulnerability (CVE-2017-11882). This vulnerability allows for arbitrary code execution upon opening the document. The ClamAV detection name confirms this exploit. The primary goal is likely to download and execute a secondary payload, although no specific download URLs or scripts were extracted from this sample.

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_off000016f4.bin rtf-objdata-decoded RTF \objdata at offset 0x16F4 37228 bytes
SHA-256: b7b88fed889245a4ed3498af214f2654b6caaccdc8c100252eb990450d078f1f