Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4b560bc597c2911…

MALICIOUS

PDF

14.1 KB
MD5: 6974181ef028044b19fa797a045a7b29 SHA-1: d1f88b908f12eb78f57381513dcbd68020e0a3b6 SHA-256: a4b560bc597c2911ec3a4bfbdebe4ba62ae34a739c9ef435e43ada09e11e5e08
124 Risk Score

Malware Insights

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

The critical ClamAV detection and high-severity heuristic for an XFA title base-26 eval stager indicate this PDF is designed to exploit vulnerabilities. The presence of embedded files and an XFA form further supports this. The embedded URL, while seemingly benign, is likely part of the exploit chain or a lure. The primary attack pattern involves leveraging XFA and potentially JavaScript to execute malicious code, leading to the download of a secondary payload.

Heuristics 6

  • ClamAV: Pdf.Exploit.Agent-36962 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36962
  • XFA title base-26 eval stager high PDF_XFA_TITLE_BASE26_EVAL_STAGER
    PDF XFA initialize script reads an encoded payload from the document title, builds event.target.eval and String.fromCharCode from string fragments, decodes base-26 character pairs, and evals the recovered stage. This is an exploit-kit staging pattern; the static bytes do not prove a specific CVE by themselves.
  • 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 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.xfa.org/schema/xfa-locale-set/2.1/

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0041.bin
c06dcd026a7ea0536b63e07ce688691b585339a3ab7ff59065e546b56308c7bb
pdf-embedded-file PDF EmbeddedFile object 41 at offset 0x2AC0 85 bytes
embedded_file_obj0042.bin
dda0835df994b8be920f715db36452f6cee7bb42bbc9c897f878a7b298ba8e91
pdf-embedded-file PDF EmbeddedFile object 42 at offset 0x2B72 1029 bytes
embedded_file_obj0043.bin
d7f7bd6434fff4670f50233bfe5cf596fac9d4d44d97771942e495ed6801d5e8
pdf-embedded-file PDF EmbeddedFile object 43 at offset 0x2D8B 1949 bytes
embedded_file_obj0044.bin
3dd68f00f4fcb366a2a3a17c65cb2626eeddf5ea5713302d374310561d810169
pdf-embedded-file PDF EmbeddedFile object 44 at offset 0x3212 144 bytes
embedded_file_obj0045.bin
10c03f88a5f0a0833dc5b2c8ac295b3a3c6f65e23889eb8cc1dc6fe29bf7f275
pdf-embedded-file PDF EmbeddedFile object 45 at offset 0x32BE 77 bytes