Malicious RTF — malware analysis report

Static analysis result for SHA-256 ac4fff612604828f…

MALICIOUS

RTF

15.6 KB First seen: 2018-07-27
MD5: 4f5fb3c74a8224ab8850f3ef846cef95 SHA-1: 720c766f7a4dd28f9821f15b0e49c07fc5d98e29 SHA-256: ac4fff612604828ff158e8a69463fce5d4c53e4420e2abc0d0038644e7da1e9c
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 vulnerabilities (CVE-2017-11882). The presence of ` tf_objupdate` and `rtf_ole10native_stream` further indicates an attempt to activate embedded content. ClamAV detection confirms this as a known exploit targeting Equation Editor, commonly used to deliver secondary payloads.

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_off00001a10.bin rtf-objdata-decoded RTF \objdata at offset 0x1A10 4645 bytes
SHA-256: a5ff212e287ac04ac9232de7292dc8174c136cc1b2292e265e49fd019c4d2747