Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4c5c24a839706a8…

MALICIOUS

PDF

38.5 KB Created: 2021-05-15 03:37:01 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 91859c57fa22fa2c37fb6f3055f0f99a SHA-1: f98d66b436627b67fc34f8a89a894c77a35d36cd SHA-256: b4c5c24a839706a89d68bc24664aaf7379543247ca7dea173c95cb6a8042347b
170 Risk Score

Malware Insights

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

The PDF document contains embedded links that impersonate the eBay brand, directing users to a URL associated with game hacks and free currency. This is a common tactic for credential phishing or redirecting users to malicious sites. The presence of multiple critical heuristic firings related to malicious redirectors and brand impersonation strongly supports this attack pattern.

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.
  • Brand-impersonation credential phishing lure high SE_BRAND_CREDENTIAL_PHISH
    Document impersonates a well-known consumer brand and uses account-security / verification language ('unusual activity', 'account on hold', 'verify your account') to steer the reader to a credential-harvesting link. Corroborated by: call-to-action link host does not match the impersonated brand: https://netcdn.xyz/app/431946152/free-roblox-accounts-with-robux-that-work-not-banned-2021-game-hack.
  • 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/free-roblox-accounts-with-robux-that-work-not-banned-2021-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_off0000358d.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x358D 25716 bytes
SHA-256: fbae3a2f8791723d1a61f0d58af8bb554c9e74f31e6b765dc4100781e5b4c1a5
font_01_sfnt_off00007163.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7163 19652 bytes
SHA-256: 72c791ad1c4340ed85ac0ecdba514e35635851f3f818d4a167a4eafc97bf1d2a