Malicious PDF — malware analysis report

Static analysis result for SHA-256 a900b88a39ef5ec4…

MALICIOUS

PDF

41.6 KB Created: 2021-05-13 06:06:17 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7)
MD5: d3ff174a8a8e73a64dcf905030c8fe2b SHA-1: 7ed121717e460efd82b2f95cf110a57c3131f4ee SHA-256: a900b88a39ef5ec4495f5bb449d8fc76f0247f99efd00fa1d59022ec966d7690
102 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document contains a large number of external links, many of which are structured as a link farm for SEO purposes, pointing to other PDF files. The document body and embedded links suggest a lure for game hacks and cheats, likely intended to lead users to malicious websites or download further malware. The ML classifier strongly indicated maliciousness, and the PDF structure with numerous external links supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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.xyz/app/406889139/free-hacks-for-coin-master-game-hack
    • http://hometech.tw/ckfinder/userfiles/files/free-coin-master-spins-no-verification_GM406889139.pdf
    • http://hometech.tw/ckfinder/userfiles/files/coin-master-hack-2021-ios-download_GM406889139.pdf
    • http://hometech.tw/ckfinder/userfiles/files/free-robux-clothes_GM431946152.pdf
    • http://hometech.tw/ckfinder/userfiles/files/coin-master-claim-spins_GM406889139.pdf
    • http://hometech.tw/ckfinder/userfiles/files/minecraft-java-hacks_GM479516143.pdf
    • http://hometech.tw/ckfinder/userfiles/files/coin-master-free-spins-link-blogspot-2021_GM406889139.pdf
    • http://hometech.tw/ckfinder/userfiles/files/ways-to-get-free-robux-2021_GM431946152.pdf
    • http://hometech.tw/ckfinder/userfiles/files/coin-master-free-spins-daily-2021_GM406889139.pdf
    • http://hometech.tw/ckfinder/userfiles/files/how-to-hack-coin-master-spin-in-hindi_GM406889139.pdf
    • http://hometech.tw/ckfinder/userfiles/files/minecraft-bedrock-hacks_GM479516143.pdf
    • http://hometech.tw/ckfinder/userfiles/files/how-to-get-free-spins-and-coins-in-coin-master_GM406889139.pdf
    • http://hometech.tw/ckfinder/userfiles/files/free-robux-for-kids_GM431946152.pdf
    • http://hometech.tw/ckfinder/userfiles/files/coin-master-free-coins-hack_GM406889139.pdf
    • http://hometech.tw/ckfinder/userfiles/files/free-roblox-accounts-with-robux-that-work-2021_GM431946152.pdf
    • http://hometech.tw/ckfinder/userfiles/files/coin-master-free-spins-link-facebook_GM406889139.pdf
    • http://hometech.tw/ckfinder/userfiles/files/coin-master-hack-app-2021-download_GM406889139.pdf
    • http://hometech.tw/ckfinder/userfiles/files/how-to-download-minecraft-for-free-ios_GM479516143.pdf
    • http://hometech.tw/ckfinder/userfiles/files/minecraft-hack-client-download_GM479516143.pdf
    • http://hometech.tw/ckfinder/userfiles/files/how-to-get-free-spins-on-coin-master-2021_GM406889139.pdf
    • http://hometech.tw/ckfinder/userfiles/files/coin-master-firebird-card-free_GM406889139.pdf
    • http://en.wikipedia.org/wiki/MIT_License

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off00004824.bin
6b32534236aac3f66c02ae02e0bd6d2f09f25b127cc2480fd6c0aeb07d487072
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x4824 24888 bytes
font_01_sfnt_off00008162.bin
2beebd07a7bf3792acdee249f7a2a83ed44f2fe9f2bfb57386b991bf1122f076
pdf-font-stream PDF embedded font (sfnt) at offset 0x8162 17880 bytes