Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a9961aba3bd32ff…

MALICIOUS

PDF

13.0 KB
MD5: 67332c15f91901fe6cae8e741eddf3ed SHA-1: ba210a0eec87677cde11ed3dd56cb1eb81e5961e SHA-256: 7a9961aba3bd32ffa8dc12bd9c246eb496f98597ce73161c84f4f970ee16a3b6
218 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF file exploits CVE-2010-0188, a known vulnerability in Adobe Reader's handling of XFA forms. The embedded JavaScript shellcode contains a URL, http://liouy.asia/extension/changes_days.php?vmhlfi=0908373404&fxgna=37370238050a05040b02&xgumudd=03&iztsdjw=hdddfse&ffqq=tga, which is likely used to download and execute a secondary payload. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 8

  • Adobe Reader LibTIFF XFA image exploit — CVE-2010-0188 critical CVE likely CVE_2010_0188
    PDF contains the CVE-2010-0188 exploit template: XFA JavaScript heap-spray setup, a generated TIFF image payload, and assignment of that TIFF data to an XFA image field rawValue to trigger Adobe Reader's LibTIFF parser.
  • ClamAV: Pdf.Exploit.Agent-36962 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36962
  • PDF exploit shellcode contains an embedded download URL high PDF_JS_SHELLCODE_DOWNLOAD_URL
    Decoded PDF exploit shellcode contains a hardcoded http(s) URL — stored as little-endian %uXXXX Unicode escapes, or hex-encoded in a document metadata field (/CreationDate, /Title) and referenced from the decoded script. Reader exploit shellcode embeds the second-stage fetch URL this way and pulls it down with a urlmon/URLDownloadToFile-style download-and-execute (commodity downloader behaviour rather than a specific Acrobat CVE).
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • AcroForm button with action trigger low PDF_ACROFORM_BUTTON
    PDF contains a /Btn form field together with a SubmitForm/URI/Launch/JS trigger — this is the building block of fake 'Download' or 'Open' button overlays used in PDF phishing lures
  • Suspicious extracted artifact info 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.
  • 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://liouy.asia/extension/changes_days.php?vmhlfi=0908373404&fxgna=37370238050a05040b02&xgumudd=03&iztsdjw=hdddfse&ffqq=tga
    • http://www.xfa.org/schema/xfa-locale-set/2.1/
    • http://ns.adobe.com/xdp/
    • http://www.xfa.org/schema/xci/1.0/
    • http://www.xfa.org/schema/xfa-template/2.2/
    • http://www.xfa.org/schema/xfa-data/1.0/

Extracted artifacts 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0041.bin
c06dcd026a7ea0536b63e07ce688691b585339a3ab7ff59065e546b56308c7bb
pdf-embedded-file PDF EmbeddedFile object 41 at offset 0x26C0 85 bytes
embedded_file_obj0042.bin
dda0835df994b8be920f715db36452f6cee7bb42bbc9c897f878a7b298ba8e91
pdf-embedded-file PDF EmbeddedFile object 42 at offset 0x2772 1029 bytes
embedded_file_obj0043.bin
9c58a0994eee827abd1bc8adae7b02a4c6236f9577fb5360a2838db447a23842
pdf-embedded-file PDF EmbeddedFile object 43 at offset 0x298B 1789 bytes
embedded_file_obj0044.bin
3dd68f00f4fcb366a2a3a17c65cb2626eeddf5ea5713302d374310561d810169
pdf-embedded-file PDF EmbeddedFile object 44 at offset 0x2D9B 144 bytes
embedded_file_obj0045.bin
10c03f88a5f0a0833dc5b2c8ac295b3a3c6f65e23889eb8cc1dc6fe29bf7f275
pdf-embedded-file PDF EmbeddedFile object 45 at offset 0x2E47 77 bytes
xfa_metadata_stage_000.js
4a7e0403ed392ad3241ae2457e555b77a0db7ce2becd8a45852a009150f90bb7
deobfuscated-js XFA /title base-31 decoded JavaScript (raw) at offset 0xDE9 2181 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s). Carved artifact contains 3 long base64-like blob(s).