Malicious PDF — malware analysis report

Static analysis result for SHA-256 31cb000e4281b053…

MALICIOUS

PDF

44.7 KB Created: 2021-06-03 17:12:15 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-10-07
MD5: edb8949875590e1667154f639f5e97a0 SHA-1: d21f476d60bfba9695f33e4d7c08bd97f951444a SHA-256: 31cb000e4281b053618b4735ac9cefc6e8eaa8afef255325221e87b9070caa26
220 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains multiple links to external resources, including a primary redirector URL associated with game hacks and generators. Several heuristics indicate that this PDF is part of a link farm designed to drive traffic to potentially malicious sites. The document body, though partially corrupted, contains text related to 'free game pack' and 'coin master', reinforcing the lure. No scripts were extracted, but the presence of numerous links to known malicious redirectors and link farms strongly suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9865

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.online/app/406889139/free-game-pack-coin-master-game-hack In PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/minecraft-free_GM479516143.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/show-me-how-to-get-free-robux_GM431946152.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/free-robux-no-verification-no-download-2021_GM431946152.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/coin-master-hack-spins-download_GM406889139.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/free-game-pack-coin-master_GM406889139.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/coin-master-cards-for-free_GM406889139.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/free-robux-websites-that-actually-work_GM431946152.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/roblox-be-crushed-by-a-speeding-wall-hack-script_GM431946152.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/games-in-roblox-that-give-you-robux_GM431946152.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/coin-master-free-codes_GM406889139.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/how-you-get-free-robux_GM431946152.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/robux-hack-2021_GM431946152.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/robux-no-human-verification_GM431946152.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/how-to-get-hacks-on-roblox_GM431946152.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/wwwhaktutsin-2021-08-coinmasterfreespinandcoinlinkhtml-m-1_GM406889139.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/is-there-any-way-to-get-free-robux_GM431946152.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/coin-master-game-for-pc-free-download_GM406889139.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/how-to-get-800-robux-for-free_GM431946152.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/complete-offers-for-robux_GM431946152.pdfIn PDF document text
    • https://kejari-denpasar.go.id/public/ckfinder/userfiles/files/best-minecraft-hacked-client-2021_GM479516143.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
stream_004_off000052a0.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x52A0 24968 bytes
SHA-256: aae63216e1618ca6643d81f7c1b55a64d2b9db6f9ded1f6aeb93c41a0907c26f
font_01_sfnt_off00008c3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8C3D 18292 bytes
SHA-256: 50801c1212ba10e6fec772be1621f3a9c69628be9ab96fac5d906e32cadaa888