Malicious PDF — malware analysis report

Static analysis result for SHA-256 55d9e352bfe518ce…

MALICIOUS

PDF

12.2 KB
MD5: 63d91f6c58c65ced0a91f519cd3b9dcc SHA-1: 23422595fc7aeaf8308e3eed5b6cb17cfd961420 SHA-256: 55d9e352bfe518ce88676e178cf6fd0e94f8c114f27619c6df66616daffc9dbb
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 and a percent-decoding eval stager. This JavaScript is likely used to download and execute a second-stage payload, as indicated by the extracted files 'legacy_pdfkit_stage_000.js' and 'legacy_pdfkit_stage_001.js'. The ClamAV detection further confirms its malicious nature.

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-36065 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36065
  • 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
9c67560e8c63b720885d3efc1627b844b86a6ec08e99e5b65a22eae832045756
pdf-javascript-stream PDF /JS object 7 at offset 0x19C 431 bytes
legacy_pdfkit_stage_000.js
f40391d317449f49c4ba7e54447de44fae330d114b4b5303dc810475bda74f72
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x315 12646 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
497f485ee9e63ef958c4c20cdb5f10978a403cac34e5979d3d6ebb70cf102110
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x315 5186 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).