Malicious PDF — malware analysis report

Static analysis result for SHA-256 77db3e4578080d80…

MALICIOUS

PDF

38.6 KB Created: 2021-05-13 20:00:51 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-26
MD5: c85f102e765573d1de2c3c545b0a91d0 SHA-1: a3eb7bb6cb9eb77b546ae9500f7ecd5c8466cdc9 SHA-256: 77db3e4578080d80ea68aa56b03ae2e2f5ff4ad79d3ef51d15a1037404cc1e9f
170 Risk Score

Malware Insights

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

The PDF document contains a lure for 'free Robux' and displays a fake CAPTCHA, prompting the user to click a link. This link, 'https://netcdn.xyz/app/431946152/how-to-get-free-robux-on-phone-game-hack', is identified as a malicious redirector. The document's structure and content strongly suggest an attempt to deceive the user into executing malicious code or visiting a compromised site.

Machine Learning

  • Nyx PDF Classifier clean score 0.0334

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/how-to-get-free-robux-on-phone-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
stream_003_off00003389.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x3389 27908 bytes
SHA-256: 6bc1e2428712246d59728d54cdc5165cbbaaa2a24537eba1cecfa2460fb45114
font_01_sfnt_off000074c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x74C4 18600 bytes
SHA-256: 4aaa4dd608c1f398ea3b3714e579938e54c8b6ebc42d5b365d603cdfd05c4e85