RTF malware analysis — malicious · c4d3e517d2721c90

MALICIOUS

RTF

127.3 KB First seen: 2018-06-30

MD5: 23a097964ac3da5673519d45ded2d6b8 SHA-1: cc83515149f37563992ad228ffd7525921d1ac3f SHA-256: c4d3e517d2721c9067831b7fe130d5b8be1e061fdefb51096fa9e36247b071cf

340 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 leverages the Equation Editor vulnerability (CVE-2017-11882). The document prompts the user to enable editing, which is a lure to trigger the exploit. The exploit likely executes a second-stage payload, indicated by the critical heuristic firings and ClamAV detection.

Heuristics 8

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
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.

Filename	Kind	Source	Size
`objdata_00_off00000092.bin`	rtf-objdata-decoded	RTF \objdata at offset 0x92	43769 bytes
SHA-256: `ef357230c614dbb28c49bd958abb61ad15592bd8760a9f1e37c43234d10752b2`

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