Malicious PDF — malware analysis report

Static analysis result for SHA-256 21efd53a19d0fdd6…

MALICIOUS

PDF

35.9 KB Created: 2021-05-17 16:10:48 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 7c7f1941e64dfd4d795f1606fe94f849 SHA-1: 3fc4a46fefe80abc175fc7d8d26c5f6f4c16f140 SHA-256: 21efd53a19d0fdd6570536ea77220979e90273ef896c6f30644946a8e8da28c9
170 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF document contains multiple heuristics indicating malicious intent, including links to known malicious redirectors and a fake CAPTCHA lure. The primary URL, 'https://netcdn.xyz/app/431946152/get-free-robux-game-hack', is presented as a 'free generator' or 'game hack', designed to trick users into clicking it. The document's content and structure strongly suggest a phishing or scam attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier clean score 0.0282

Heuristics 5

  • PDF links to a 'free generator / game hack' redirector critical PDF_GAME_HACK_REDIRECT_LURE
    PDF's clickable action targets a redirector of the form /app/<id>/<slug>-game-hack — the landing-page shape of a large SEO 'free spins / generator / game hack' lure family that funnels victims through rotating disposable hosts to a malware/scam payload. The multi-link variants also trip ML/link-farm rules; this catches the single-link variants that otherwise score clean. CRITICAL on its own: the /app/<id>/<slug>-game-hack path shape is unambiguous scam infra, and the host rotates so a host-list match can't be relied on.
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://netcdn.xyz/app/431946152/get-free-robux-game-hack In PDF document text
    • http://en.wikipedia.org/wiki/MIT_LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000332b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x332B 24572 bytes
SHA-256: 62e58c725ba3f01dc46db40b74d79b9ffb89a01994afd305ac2641a89e581026
font_01_sfnt_off00006b94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6B94 18120 bytes
SHA-256: 79ac164380d838bf2943c127f808202d45f8751c05dbd036140e6fb9b1b49848