Malicious PDF — malware analysis report

Static analysis result for SHA-256 efc17b833e90cc1b…

MALICIOUS

PDF

34.8 KB Created: 2021-06-29 18:04:39 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-09-15
MD5: 7cee3ae7881c76574f7b9c5670c25801 SHA-1: d6f53e78fe4fe846a4fb02814f3ea57167c0aeaa SHA-256: efc17b833e90cc1b30759c6294f0fa23d814362216d35871c2c870be9595781d
220 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF document contains multiple links to known malicious redirectors and SEO link farms, luring users with promises of free game hacks and currency. The document body and heuristics indicate a clear intent to drive traffic to potentially malicious sites, likely for further exploitation or phishing. No scripts were extracted, but the embedded URLs and link farm structure are strong indicators of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://netcdn.co/app/431946152/robux-infinity-free-game-hack In PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/how-do-u-get-free-robux-2021_GM431946152.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/how-to-get-free-robux-on-roblox_GM431946152.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/pixies-gigantic-coin-master-free-spins-and-coins_GM406889139.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/minecraft-java-edition-redeem-code-free-2021_GM479516143.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/coin-master-free-cards_GM406889139.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/coin-master-redeem-code-free_GM406889139.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/err-face-roblox-free_GM431946152.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/coin-master-free-spin-link-today-50_GM406889139.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/how-to-get-free-robux-no-human-verification-pc_GM431946152.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/coin-master-club-hack_GM406889139.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/how-to-get-free-spins-and-coins-on-coin-master_GM406889139.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/wahoo-gaming-co-free-robux_GM431946152.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/roblox-free-robux-game-no-password_GM431946152.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/free-minecraft-server-hosting-24-7_GM479516143.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/minecraft-noob-vs-pro-vs-hacker_GM479516143.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/how-to-hack-a-roblox-accounts_GM431946152.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/roblox-redeem-card-codes-free_GM431946152.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/coin-master-hack-2021-android_GM406889139.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/how-to-hack-coins-in-archery-master-3d_GM406889139.pdfIn PDF document text
    • http://www.repion.com/uploaded_files/userfiles/files/coin-master-hack-version-2021-download_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_off00003132.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x3132 22368 bytes
SHA-256: 44bf28494cd80ba1988934706635e49a35f6b9f7b2549f109cd5a8e924f03feb
font_01_sfnt_off000062dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x62DC 19120 bytes
SHA-256: 106854da85ecbdda8bb89edd53cb4a54b558bf7dd38d0bb7423bf3932aab5475