Malicious PDF — malware analysis report

Static analysis result for SHA-256 031c98d905d30b83…

MALICIOUS

PDF

44.5 KB Created: 2021-05-10 14:41:46 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-09-24
MD5: 3190b5d95c84e642d03104374bd74c91 SHA-1: fbd2dc3191ae606548ae8f0f2ba23587eac2ad88 SHA-256: 031c98d905d30b83a840e0e9bb80c37527ab910542589fcc62abeb41008a141d
92 Risk Score

Malware Insights

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

This PDF document was flagged as malicious. It uses brand-impersonation credential phishing. The file routes users through malicious redirector infrastructure and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier clean score 0.0366

Heuristics 5

  • PDF links to a 'free generator / game hack' redirector high 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.
  • 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-robux-for-free-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
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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-robux-for-free-game-hack PDF link annotation
    • http://en.wikipedia.org/wiki/MIT_LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off00003750.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x3750 39312 bytes
SHA-256: 74c9e962425a0916e35fd9c56b5577f289573a0ecb791c9b5985a023ea0c57d3
font_01_sfnt_off00008e15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8E15 18012 bytes
SHA-256: 3ef9e48aa3d97d4217e004f7625a8cbae9320a74231b80a01553f6433e422360