Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5cfe545254fbd03…

MALICIOUS

PDF

12.2 KB
MD5: 5c5c18872b46af5e1cfbc9ddc8703e48 SHA-1: 6ea521149f18fe617db5f55cc100db5265b9980a SHA-256: f5cfe545254fbd03667eea80ec21f0694998934599c81cefa5dc56dd8bf944c0
198 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link

The PDF file contains obfuscated JavaScript, identified by heuristics as exploiting CVE-2007-5659 via the Collab.collectEmailInfo function. This JavaScript acts as a stager, designed to download and execute a second-stage payload from a remote source. The presence of multiple deobfuscated JavaScript files further indicates a multi-stage attack. The primary goal appears to be the execution of arbitrary code through the exploitation of a known PDF vulnerability.

Heuristics 6

  • Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659
    PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (identified after JavaScript deobfuscation)
  • Annotation subject percent-decoding eval stager critical PDF_ANNOT_SUBJECT_MARKER_EVAL_STAGER
    OpenAction JavaScript forces annotation enumeration, reads an annotation /Subject payload with getAnnots(), rewrites marker bytes into percent escapes, decodes it with unescape(), and dispatches it through eval. This is a high-confidence exploit-kit staging pattern. It is intentionally not mapped to CVE-2009-1492 unless getAnnots() itself carries the crafted integer or long argument shape for that vulnerability.
  • ClamAV: Heuristics.PDF.ObfuscatedNameObject critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Heuristics.PDF.ObfuscatedNameObject
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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.

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
6f60a1053baafdc578f85eae84a2dc6d16775fbd66240d82cbfb7b4f4ff4e90a
pdf-javascript-stream PDF /JS object 7 at offset 0x19D 295 bytes
legacy_pdfkit_stage_000.js
188d26ec7654f37aad70fab42e6de6a813171a78d1923a278a4e7d662a5a7957
deobfuscated-js z-percent hex-pair decoded JavaScript at offset 0x2E9 5227 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
b28a44f61a0767549bdb6e8c7bb9da42152532c8d7712d85e4864829d88cb2be
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2E9 12484 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).