Malicious PDF — malware analysis report

Static analysis result for SHA-256 dcb9fc28f7c121a7…

MALICIOUS

PDF

9.5 KB
MD5: 10c2170824f63ab8ef98280fba5e1a99 SHA-1: c9facead77d498b4882d419926ccb8a08b02d0c6 SHA-256: dcb9fc28f7c121a70e8c736787b1d7c02610cb201b4e4adcf05ac2f04abf83d1
126 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' function, which is associated with CVE-2007-5659. This function is used to decode and execute a hex-encoded JavaScript stager. The stager is responsible for downloading and executing a second-stage payload, indicating a downloader or dropper attack pattern. The high confidence is due to the critical heuristic firing and the clear exploitation of a known CVE.

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 callee-key hex JavaScript stager high PDF_ANNOT_SUBJECT_CALLEE_HEX_STAGER
    PDF JavaScript uses syncAnnotScan()/getAnnots() to read an indirect annotation /Subject stream, percent-decodes it through marker replacement, then uses a callee.toString()-derived key to decode and eval the final exploit stage.
  • 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.
  • syncAnnotScan annotation-staging primitive low PDF_FOXIT_SYNCANNOTSCAN
    PDF JavaScript calls syncAnnotScan() — a no-op annotation-enumeration primitive used by exploit-kit JavaScript to stage payload reads from annotation /Subject fields before eval(). Not a vulnerable sink itself; rarely seen in legitimate PDFs. (matched in decompressed stream)
  • 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
b9a85ee399db318b3ad68d0755effe289a645a7404fad2094712c8a3fd042920
pdf-javascript-stream PDF /JS object 7 at offset 0x19B 244 bytes
annotation_subject_callee_hex_stage_000.js
e5d3dcc7e698cc358b5a9ad49988cf95e740f768d3846ced3ad130a425038b46
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x14A 5044 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
cb709b842a300f0eafb57ea5fac0b325b5a06461dcbdcaf705f1db12415ffa4c
deobfuscated-js PDF JavaScript deobfuscation pass 70705 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).