Malicious PDF — malware analysis report

Static analysis result for SHA-256 23a543c360938762…

MALICIOUS

PDF

44.4 KB Created: 2021-05-19 16:35:30 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-09-17
MD5: 8ad7bfcde91c2b15d8876d9fd31977af SHA-1: 076611a01397f9fa5dc49cfbe578484889653261 SHA-256: 23a543c360938762bd85f3b9d4ae86ec8406eaf3647a0f901308a138b1506af0
102 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to other PDF files hosted on 'licko.cz', suggesting a link farm designed to distribute potentially malicious content. The presence of a 'download button' heuristic and the ML classifier's high confidence score further support the malicious nature of this document. The primary goal appears to be directing users to external resources offering game cheats and hacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9632

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/http-bit.ly-coin-master-free-2021-spins-game-hack PDF link annotation
    • http://licko.cz/files/get-free-robux-without-doing-anything_GM431946152.pdfIn PDF document text
    • http://licko.cz/files/get-gold-coin-master-village-hack_GM406889139.pdfIn PDF document text
    • http://licko.cz/files/roblox-arsenal-hack-script-pastebin_GM431946152.pdfIn PDF document text
    • http://licko.cz/files/coin-master-free-cards-link-2021_GM406889139.pdfIn PDF document text
    • http://licko.cz/files/coin-master-20-free-spins-link-today_GM406889139.pdfIn PDF document text
    • http://licko.cz/files/free-roblox-codes-2021_GM431946152.pdfIn PDF document text
    • http://licko.cz/files/coin-master-hack-2021-without-human-verification_GM406889139.pdfIn PDF document text
    • http://licko.cz/files/how-to-win-free-robux_GM431946152.pdfIn PDF document text
    • http://licko.cz/files/minecraft-redeem-code-free_GM479516143.pdfIn PDF document text
    • http://licko.cz/files/free-robux-websites-no-human-verification_GM431946152.pdfIn PDF document text
    • http://licko.cz/files/lucky-patcher-coin-master-hack_GM406889139.pdfIn PDF document text
    • http://licko.cz/files/strucid-aimbot_GM431946152.pdfIn PDF document text
    • http://licko.cz/files/free-robux-hack_GM431946152.pdfIn PDF document text
    • http://licko.cz/files/rbx-place-free-robux_GM431946152.pdfIn PDF document text
    • http://licko.cz/files/infinite-robux_GM431946152.pdfIn PDF document text
    • http://licko.cz/files/minecraft-pe_GM479516143.pdfIn PDF document text
    • http://licko.cz/files/how-to-get-free-unlimited-robux_GM431946152.pdfIn PDF document text
    • http://licko.cz/files/free-robux-hacker-us_GM431946152.pdfIn PDF document text
    • http://licko.cz/files/coin-master-hack-spins-ios_GM406889139.pdfIn PDF document text
    • http://licko.cz/files/minecraft-switch-free_GM479516143.pdfIn PDF document text
    • http://en.wikipedia.org/wiki/MIT_LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off000046d9.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x46D9 24704 bytes
SHA-256: 06e3e75143a52f8206b1340a12cbae653f12069b7273fcbbab6dea3d29e89f3f
font_01_sfnt_off00007fb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7FB6 2840 bytes
SHA-256: 3fb127b764b9d10f5525bc4de5ec8316de704409ccb0cf21cff3ad8a30d11676
font_02_sfnt_off00008968.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8968 18824 bytes
SHA-256: 7e3049b9a5a0ae93670f4a3987e867be19f2251f6b8a6c3356ce1f88b75303f6