Malicious PDF — malware analysis report

Static analysis result for SHA-256 380a660aa5c0cf9d…

MALICIOUS

PDF

17.0 KB
MD5: 3f24bebd9b5fa3cf4e9267fc05eb9d28 SHA-1: e386a6b1fb9afbbefc7d27ffd31df64d00a07da8 SHA-256: 380a660aa5c0cf9d9c6cf1c33d66bd34bb9d3ffe8823354fc7c0a47040ba6add
234 Risk Score

Malware Insights

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

This PDF file exploits CVE-2007-5659 using a JavaScript stager embedded within an annotation subject. The JavaScript is heavily obfuscated and employs multiple anti-analysis techniques. It appears to function as a multi-stage dropper, ultimately leading to the execution of malicious code. The specific payload and its ultimate destination could not be fully determined due to the obfuscation, but the exploit chain is clear.

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)
  • ClamAV: Pdf.Exploit.Agent-35901 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35901
  • 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 2 related findings PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Obfuscated multi-stage PDF JavaScript dropper high PDF_JS_OBFUSCATED_DROPPER
    PDF JavaScript shows 4 independent signals of exploit-kit-style multi-stage obfuscation: annot_subject_stage, hex_codec_loop, incremental_eval_build, repeated_pluginschk. This is strongly consistent with pre-2011 Adobe Reader PDF droppers — OpenAction JS reads encoded data from annotation subjects, decodes it through one or more hex / base-N loops, and invokes eval indirectly (method name built one character at a time). The actual CVE is hidden in the final decoded layer and is not visible via static analysis.
  • 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_obj0009_000.js
4718a27c2224fc36bf24f8e8e04598f1ad78adce4401c7be2708318738a6983d
pdf-javascript-stream PDF /JS object 9 at offset 0x418A 469 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
annotation_subject_callee_hex_stage_000.js
4f17761936ab23d79f58a23aec98f08ebf263e22651d54688212aa9ffe8b88d0
deobfuscated-js annotation-subject callee-key decoded JavaScript at offset 0x1A93 5313 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
deobfuscated.js
2659b6823e3e7e94d051e282121f03f56360d30a9e37e582f926210a8009adde
deobfuscated-js PDF JavaScript deobfuscation pass 87334 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 10 eval/decoder/string-building token(s). Carved artifact contains 3 long base64-like blob(s).