Malicious PDF — malware analysis report

Static analysis result for SHA-256 31ec8374e79087a1…

MALICIOUS

PDF

46.4 KB Created: 2021-06-10 23:25:02 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7)
MD5: 14a71cca7d02b3e1eba52309586f0e69 SHA-1: 9c86f1187291eb4180ae6943828b877b3a71c4ae SHA-256: 31ec8374e79087a1a968e7ab2065e39102f4e167cd37ffc48c48707bc223524e
102 Risk Score

Malware Insights

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

The PDF document contains multiple links to external websites, including one that promises free Robux in exchange for downloading a file. The ML classifier strongly indicates maliciousness, and the PDF structure suggests a link farm designed to distribute potentially harmful content. The primary goal appears to be tricking users into downloading a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9832

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 https://netcdn.tw/app/431946152/get-robux-in-roblox-free-game-hack
    • http://www.furuihp.com/Public/upload/editorfiles/roblox-executor-free_GM431946152.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/free-robux-redeem-codes-2021_GM431946152.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/free-coin-master-spins-blog_GM406889139.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/how-to-get-roblox-premium-for-free-2021_GM431946152.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/coin-master-free-spins-link-hack_GM406889139.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/hacks-para-atravesar-paredes-en-roblox_GM431946152.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/tiktok-fans-free_GM835599320.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/easy-way-to-get-free-robux_GM431946152.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/free-spins-on-coin-master-2021_GM406889139.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/free-robux-without-downloading-anything_GM431946152.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/coin-master-cheats-without-verification_GM406889139.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/free-robux-without-verification-2021_GM431946152.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/coin-master-free-spins-no-human-verification_GM406889139.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/free-robux-games-on-roblox_GM431946152.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/play-coin-master_GM406889139.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/how-to-get-free-robux-on-iphone_GM431946152.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/free-spins-on-coin-master-hack_GM406889139.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/buy-robux-free_GM431946152.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/totally-free-coin-master-spins-2021_GM406889139.pdf
    • http://www.furuihp.com/Public/upload/editorfiles/free-minecraft-skins-xbox-one_GM479516143.pdf
    • http://en.wikipedia.org/wiki/MIT_License

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00005184.bin
e06254f321f6fc9ea8fc6d8a1d4e879e68539a425170e134dd7bb5b78c306ef0
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x5184 28712 bytes
font_01_sfnt_off0000930b.bin
c23a7f5e8e88560acefdb30b9594586780e661aeaa5303652099f8100b30dc50
pdf-font-stream PDF embedded font (sfnt) at offset 0x930B 18192 bytes