Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5c3610fafa4b9e9…

MALICIOUS

PDF

34.0 KB Created: 2021-07-07 09:30:30 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7)
MD5: 705985f28e41b7e948414453903f072d SHA-1: 6d45f08493ec2ea2c02c0398993891b646002ad8 SHA-256: b5c3610fafa4b9e9c0323417b359775a4e7f6dd7632ccbf85e6799b4a4a6cdd6
102 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous links to external resources, many of which are hosted on domains associated with SEO link farms. The primary URL, http://netcdn.tw/app/431946152/getrobux-info-game-hack, suggests a lure for free in-game currency, likely to trick users into downloading a malicious payload. The ML classifier strongly indicated maliciousness, and the presence of a download button lure further supports this. No scripts were extracted, but the overall structure and linked content point to a downloader or phishing attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 4

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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 http://netcdn.tw/app/431946152/getrobux-info-game-hack
    • https://edu.kyst.com.tw/image/data/files/free-robux-for-kids-no-verification_GM431946152.pdf
    • https://edu.kyst.com.tw/image/data/files/youtube-roblox-hack-robux_GM431946152.pdf
    • https://edu.kyst.com.tw/image/data/files/shadowrun-cheat-codes-roblox_GM431946152.pdf
    • https://edu.kyst.com.tw/image/data/files/clean-master-free-coins-and-spins_GM406889139.pdf
    • https://edu.kyst.com.tw/image/data/files/coin-master-free-spins-hack-iphone_GM406889139.pdf
    • https://edu.kyst.com.tw/image/data/files/coin-master-free-spins-android_GM406889139.pdf
    • https://edu.kyst.com.tw/image/data/files/blogger-coin-master-free-spins_GM406889139.pdf
    • https://edu.kyst.com.tw/image/data/files/free-robux-no-very_GM431946152.pdf
    • https://edu.kyst.com.tw/image/data/files/how-to-make-a-roblox-hack-with-notepad_GM431946152.pdf
    • https://edu.kyst.com.tw/image/data/files/robux-free-robux_GM431946152.pdf
    • https://edu.kyst.com.tw/image/data/files/free-robux-tool-download-works_GM431946152.pdf
    • https://edu.kyst.com.tw/image/data/files/coin-master-free-daily-spins_GM406889139.pdf
    • https://edu.kyst.com.tw/image/data/files/coin-master-free-stuff_GM406889139.pdf
    • https://edu.kyst.com.tw/image/data/files/archery-master-3d-coins-hack_GM406889139.pdf
    • https://edu.kyst.com.tw/image/data/files/coin-master-hack-tool-v1-9-download-free-pc_GM406889139.pdf
    • https://edu.kyst.com.tw/image/data/files/www-coin-master-hack-xyz_GM406889139.pdf
    • https://edu.kyst.com.tw/image/data/files/get-roebucks-com_GM431946152.pdf
    • https://edu.kyst.com.tw/image/data/files/hack-coin-master-for-free_GM406889139.pdf
    • https://edu.kyst.com.tw/image/data/files/hack-de-robar-cuentas-de-roblox_GM431946152.pdf
    • https://edu.kyst.com.tw/image/data/files/coin-master-free-spin-and-trading-group_GM406889139.pdf
    • http://en.wikipedia.org/wiki/MIT_License

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00002fd1.bin
365f07b8dd280194407e8f47f7fcecc33626e79f12d8d2a0534765905376ecba
pdf-font-stream PDF embedded font (sfnt) at offset 0x2FD1 22176 bytes
font_01_sfnt_off000060ff.bin
dc0a3c3c5acdce1f00df61ff0cd7230377149e24fc46f8acb7cd7add040d8ac7
pdf-font-stream PDF embedded font (sfnt) at offset 0x60FF 18656 bytes