Malicious PDF — malware analysis report

Static analysis result for SHA-256 83b5081d0e333ecb…

MALICIOUS

PDF

49.8 KB Created: 2021-06-09 16:37:28 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-24
MD5: ee743daecc1ffe28eed0b52e5625f7a3 SHA-1: 0ea64d840e1ed4e094ce3171bb24be2e68e95d60 SHA-256: 83b5081d0e333ecb7301364f5e91e0c3203b64d091ba8adfbf20225321181746
220 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple links, including one identified as a 'free generator / game hack' lure, which redirects to a malicious URL. The document body, though heavily obfuscated, contains references to 'Robux Cheat App' and the malicious URL, reinforcing the phishing pretext. The presence of numerous linked PDFs suggests a link farm designed to distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9796

Heuristics 5

  • PDF links to a 'free generator / game hack' redirector critical PDF_GAME_HACK_REDIRECT_LURE
    PDF's clickable action targets a redirector of the form /app/<id>/<slug>-game-hack — the landing-page shape of a large SEO 'free spins / generator / game hack' lure family that funnels victims through rotating disposable hosts to a malware/scam payload. The multi-link variants also trip ML/link-farm rules; this catches the single-link variants that otherwise score clean. CRITICAL on its own: the /app/<id>/<slug>-game-hack path shape is unambiguous scam infra, and the host rotates so a host-list match can't be relied on.
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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
  • 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/robux-cheat-app-game-hack In PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/roblox-army-free-robux_GM431946152.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/minecraft-marketplace-free_GM479516143.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/free-robux-generator-for-roblox-2021_GM431946152.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/how-to-get-free-robux-website_GM431946152.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/free-coin-coin-master_GM406889139.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/coin-master-free-spin-download_GM406889139.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/free-spin-coin-master-apk_GM406889139.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/how-to-hack-coin-master-apple_GM406889139.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/free-robux-com-no-verification_GM431946152.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/free-roblox_GM431946152.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/where-to-get-free-robux_GM431946152.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/free-robux-real-working_GM431946152.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/roblox-phantom-forces-uncopylocked-how-to-make-all-guns-free_GM431946152.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/official-coin-master-free-spins_GM406889139.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/coin-master-free-spin-link-twitter_GM406889139.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/roblox-free-clothes-hack_GM431946152.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/how-to-join-someones-game-on-roblox-without-hacks-codes_GM431946152.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/hacks-roblox-menu_GM431946152.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/how-to-find-free-robux_GM431946152.pdfIn PDF document text
    • http://stikgiamakassar.ac.id/digilib/repository/free-robux-generator-no-verification-required_GM431946152.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_004_off00005206.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x5206 31496 bytes
SHA-256: 58b806361d10d8c1c63d304355ef18163f9facd441f47ad918859171b4e88d08
font_01_sfnt_off00009576.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9576 2832 bytes
SHA-256: 77ae1c4cffa647a8fd533dfa4102e94364989f9e80b9cd131876e9d1005899a2
font_02_sfnt_off00009f26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9F26 18524 bytes
SHA-256: b81f64b95adb81568290532664904117bc1d9a14752dd3cb0483599a527cd8d5

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