Malicious RTF — malware analysis report

Static analysis result for SHA-256 c4b26267691628d5…

MALICIOUS

RTF

257.1 KB First seen: 2018-06-21
MD5: ca5ca9ce81db5605ca97b01cdf6b1cc3 SHA-1: f0cbbf1226a7b13dd95213f247cc990516171388 SHA-256: c4b26267691628d517f720fff73d64439c697025396d1b6c2bfa8c0ae69454c0
240 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 exploits a known vulnerability in Microsoft Equation Editor (CVE-2017-11882). The document also contains a lure to 'ENABLE EDITING', indicating it's designed to trick users into activating the exploit. The ClamAV detection signature confirms the exploit's nature.

Heuristics 6

  • 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
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000062.bin rtf-objdata-decoded RTF \objdata at offset 0x62 76588 bytes
SHA-256: 3b73c17ee1abdb0e6412b27febdce6454e58c7488a69366e5ce980c4580101c9