Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5ef7798a36b6f9e…

MALICIOUS

PDF

12.9 KB
MD5: 46b32240273e6592381fe5da07152bbb SHA-1: 1ad6c4f1fcccecacd977114f9d01cd799ac711a5 SHA-256: a5ef7798a36b6f9eaefd21cb38e6bfefec4454c7c64333e3e39a96b3e266cf09
200 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, triggered by the 'Collab.collectEmailInfo' method, which is known to be vulnerable (CVE-2007-5659). The embedded JavaScript is obfuscated and appears to be a stager designed to download and execute a second-stage payload. The heuristic 'PDF_ANNOT_SUBJECT_MARKER_EVAL_STAGER' and the presence of deobfuscated JavaScript files indicate a multi-stage attack. The primary IOC is the JavaScript evaluation string used in the annotation subject.

Heuristics 7

  • 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: Pdf.Exploit.Agent-36062 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36062
  • 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.
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser exited 1. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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
068944f8c011a88ab770b45c6de142b9305a1f515d410204d5eadd9ac2b5bfb3
pdf-javascript-stream PDF /JS object 7 at offset 0x19B 373 bytes
legacy_pdfkit_stage_000.js
4b75bf7612f52aabadac79b9c442b9135584168f943a664e45596d134fc96127
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2F5 12697 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
2186a8bbb43de0d673aada69abc9e14dc52787f990fd2fd17518c0d2ab9a2c30
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2F5 5276 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).