Malicious RTF — malware analysis report

Static analysis result for SHA-256 41bb7da9c69408bf…

MALICIOUS

RTF

634.1 KB First seen: 2018-06-21
MD5: a6b9dc1601eeba647142a99295e9659e SHA-1: 3bf1ac07092d5dc30150ca3bd620a52e38bbc6a9 SHA-256: 41bb7da9c69408bf5bffcdbd85cf22a8fb18897a3200e616fce2458d42f50e4a
462 Risk Score

Malware Insights

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

The RTF file contains multiple indicators of exploitation targeting Microsoft Equation Editor, including critical firings for RTF_EQUATION_EDITOR and RTF_MZ_HEX. The presence of an embedded OLE object with an INCLUDETEXT/INCLUDEPICTURE remote URL suggests the document attempts to download and execute a secondary payload from the specified URL. The ClamAV detection of 'Win.Packer.MalwareCrypter-6642003-1' further supports the malicious nature of the file.

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
  • Composite Moniker in RTF OLE object high CVE related RTF_COMPOSITE_MONIKER_RELATED
    RTF contains Composite Moniker CLSID in OLE object context, but no nearby scriptlet/SCT payload was confirmed. Treat as related moniker attack-surface evidence rather than proof of CVE-2017-8570 exploitation.
  • ClamAV: Win.Packed.ImminentMonitorRAT-10019612-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Packed.ImminentMonitorRAT-10019612-0
  • 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.
  • INCLUDETEXT/INCLUDEPICTURE remote URL high RTF_INCLUDE_REMOTE
    RTF document uses INCLUDETEXT or INCLUDEPICTURE with an http:// URL — Word can fetch the remote content on open depending on Office version and external-content settings, enabling remote template injection, NTLM capture via redirects, or payload delivery
  • 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 7 \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://itest1.ru/newbuild/t.php?thread=0&stats=send In RTF body

Extracted artifacts 7

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000867b.bin rtf-objdata-decoded RTF \objdata at offset 0x867B 400 bytes
SHA-256: fa79b00817f7495218632b8aca05100fc72b724a674512e970aa8642ceaa44bc
objdata_01_off000089d5.bin rtf-objdata-decoded RTF \objdata at offset 0x89D5 295610 bytes
SHA-256: a7e23a84bf568f60e71d140d6aff5dcdae44cac83b94f491e1067db40500ab47
Detection
ClamAV: Win.Packed.ImminentMonitorRAT-10019612-0
Obfuscation or payload: unlikely
objdata_02_off00098f8e.bin rtf-objdata-decoded RTF \objdata at offset 0x98F8E 369 bytes
SHA-256: 338e71905e7d912ec27b0c9a9855f2581e592611183df26bee7c4ccfe9bcd35f
objdata_03_off000992ac.bin rtf-objdata-decoded RTF \objdata at offset 0x992AC 2352 bytes
SHA-256: e961bf4fa70bd245f65ffa24c14ff473f07262c52a7a2871f7a05e49df2defce
objdata_04_off0009a54a.bin rtf-objdata-decoded RTF \objdata at offset 0x9A54A 727 bytes
SHA-256: 92b12466cc9a09198d1718a0c3c9615881a1bdeaa0e674afc8c64c7380214ef9
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript" & ".Shell")
objdata_05_off0009ab89.bin rtf-objdata-decoded RTF \objdata at offset 0x9AB89 2620 bytes
SHA-256: 81d2d72fa68faccfc5765f360b95119de11eee1b7d2fa26b02fb47a3c3ef946b
objdata_06_off0009c192.bin rtf-objdata-decoded RTF \objdata at offset 0x9C192 4681 bytes
SHA-256: 75bdf0d3e6198ce8609d72f965634443d1596df6ed427f655b94bb1d92e195e5

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