Malicious PDF — malware analysis report

Static analysis result for SHA-256 3bb9af460df6c55e…

MALICIOUS

PDF

33.6 KB Created: 2021-07-04 05:51:15 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7)
MD5: 0fbfef900566d7fc220cd9cdc1b585c4 SHA-1: a51e1a1c62f264f3400b5e85714752288085e478 SHA-256: 3bb9af460df6c55e75f0bf7ada40084666719219469c4feae7d214ab2cd7011f
102 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous embedded URLs and a document body that promotes "free Robux" and "free Minecraft" themes, indicative of a lure for potentially malicious downloads. The ML classifier strongly flagged this PDF as malicious, and the presence of a link farm heuristic further supports malicious intent. While no scripts were directly extracted, the embedded URLs are the primary mechanism for delivering a second-stage payload.

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/uprobuxcom-free-robux-game-hack PDF link annotation
    • http://www.duchem.ae/uploaded_files/userfiles/files/free-roblox-rs_GM431946152.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/how-to-download-minecraft-for-free-on-mac_GM479516143.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/how-to-get-free-robux-com_GM431946152.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/coin-master-free-spins-link-2021_GM406889139.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/public-enemy-sun-prairie-coin-master-free-spins_GM406889139.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/free-spins-coin-master-no-verification_GM406889139.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/free-coins-coin-master-haktuts_GM406889139.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/minecraft-mod-menu_GM479516143.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/itv-television-centre-roblox-free_GM431946152.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/how-to-change-your-username-on-roblox-for-free-2021_GM431946152.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/how-do-you-get-free-roblox-in-youtube_GM431946152.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/minecraft-free-ios-2021_GM479516143.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/best-free-minecraft-servers_GM479516143.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/easy-robux-today-com_GM431946152.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/free-roblox-stampycat-tshirts_GM431946152.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/girl-roblox-avatar_GM431946152.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/rbx-place-free-robux_GM431946152.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/free-robux-kid-friendly-no-human-verification_GM431946152.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/new-free-spins-coin-master_GM406889139.pdfIn PDF document text
    • http://www.duchem.ae/uploaded_files/userfiles/files/free-spins-for-coin-master-2021_GM406889139.pdfIn PDF document text
    • http://en.wikipedia.org/wiki/MIT_LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00002d8c.bin
43344ebe9fea018bf0aa60a9d0d4c6723c283b48e565722ee4c3c0ccf93a9cfd
pdf-font-stream PDF embedded font (sfnt) at offset 0x2D8C 21960 bytes
font_01_sfnt_off00005ddd.bin
77e1d77af257f2799f450e4aedc0e1b3eb2c97b8c20e190c5e1e9f2e5b207ac7
pdf-font-stream PDF embedded font (sfnt) at offset 0x5DDD 19152 bytes