RTF malware analysis — malicious · 405da76b1d109a7b

MALICIOUS

RTF

161.1 KB Authoring application: Riched20 6.3.9600 First seen: 2019-05-31

MD5: 9554ac8df1912186371e77ecd85caa2f SHA-1: 7a7c0c5dd3ee27c7cb6def3997fe6c1499122493 SHA-256: 405da76b1d109a7be1c04d77dff31ea9698cd50c61b10de2112c2714c243500a

482 Risk Score

Malware Insights

MITRE ATT&CK

T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The RTF file contains an embedded OLE object that exploits the CVE-2017-11882 vulnerability in the Equation Editor. This exploit is designed to execute arbitrary code, likely a second-stage payload. The presence of shellcode API strings and command strings in extracted artifacts further supports this. The URL http://www.zeustech.net/ is associated with unknown reputation and may be a command and control server or payload host.

Heuristics 11

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: Win.Trojan.MSShellcode-7 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Win.Trojan.MSShellcode-7
PE header (with DOS stub) in hex data critical RTF_MZ_HEX

Hex-encoded PE (MZ + DOS stub) found inside RTF — likely an embedded executable payload
\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.
Package object class high RTF_OBJCLASS_PACKAGE

OLE Package object — can wrap arbitrary files
Suspicious extracted artifact high 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.
OLE object data medium RTF_OBJDATA

RTF contains 3 \objdata section(s) — embedded OLE objects
Embedded OLE object medium RTF_OBJEMB

RTF contains \objemb — embedded OLE object
OlePres presentation stream in RTF OLE object medium RTF_OLEPRES_STREAM

RTF contains an embedded OLE object with an OlePres presentation stream. OlePres is an OLE presentation marker and is not enough on its own to identify CVE-2025-21298.
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 http://www.zeustech.net/ In RTF body
- http://]hostname[:port]/pathIn RTF body
- http://www.apache.org/In RTF body

Extracted artifacts 3

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`objdata_00_off000000ed.bin`	rtf-objdata-decoded	RTF \objdata at offset 0xED	74033 bytes
SHA-256: `e4accb2e31b75c6b68fee3f1357616ce85523dc531e9dce35cb8793aa53b63cc`
Detection ClamAV: Win.Trojan.MSShellcode-7 Obfuscation or payload: likely Static shellcode analysis found candidate code region(s). Indicators: SC_PEB_ACCESS, SC_MSF_REVERSE, SC_PUSH_STRING Static shellcode analysis recovered API/import strings: kernel32.dll, advapi32.dll, KERNEL32.DLL, ADVAPI32.DLL, LoadLibraryA, GetProcAddress
`objdata_01_off0002439e.bin`	rtf-objdata-decoded	RTF \objdata at offset 0x2439E	3980 bytes
SHA-256: `de8fb7d198a9bac175bc34c3f1aac9ffb16d079c322fbd498ade0fb87f665aaa`
Detection ClamAV: No threats found Obfuscation or payload: likely Static shellcode analysis recovered command string(s): cmd.exe /c%tmp%\trojan.exe &��D$,f-Q��%
`objdata_02_off000265d8.bin`	rtf-objdata-decoded	RTF \objdata at offset 0x265D8	3546 bytes
SHA-256: `d567d72cc313973b802b2823bf014ba577af6c88e2997bd28a07856514beabba`
Detection ClamAV: No threats found Obfuscation or payload: likely Static shellcode analysis recovered command string(s): cmd.exe /c%tmp%\trojan.exe AC

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