Malicious RTF — malware analysis report

Static analysis result for SHA-256 5c99c2ef3edeb1e5…

MALICIOUS

RTF

8.1 KB First seen: 2018-08-26
MD5: f6d97a1640f1dd6376fb0319a3ca960d SHA-1: c6de98ba946511e2708b931a875c8ee47b9d4433 SHA-256: 5c99c2ef3edeb1e551bc699f67567330f6463863b596f6eb6b9a85f7c134a469
320 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object with a CLSID associated with Equation Editor, specifically triggering the CVE-2017-11882 vulnerability. This exploit is designed to execute arbitrary code, likely leading to the download and execution of a secondary payload. The presence of the Ole10Native stream and the objupdate directive further confirm the exploitation attempt.

Heuristics 7

  • 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
  • Equation Editor Ole10Native payload — CVE-2017-11882 likely critical CVE likely CVE_2017_11882_EQUATION_OLE10NATIVE
    RTF decodes to an activated Microsoft Equation 3.0 OLE storage whose payload is a high-entropy Ole10Native stream rather than normal Equation Native/MTEF data. This is a weaponized Equation Editor RCE delivery shape consistent with CVE-2017-11882/CVE-2018-0802.
  • 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
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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_off0000003f.bin rtf-objdata-decoded RTF \objdata at offset 0x3F 4130 bytes
SHA-256: 99f7a3887d18b2da7e69e716dc37f8de48787cca364f80324bc45fa571ac9a69

Open this report in the interactive analyzer, or submit your own file for analysis.