Malicious PDF — malware analysis report

Static analysis result for SHA-256 2fd11acc5dffc9bd…

MALICIOUS

PDF

48.4 KB Created: 2021-06-10 20:04:24 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-09-25
MD5: cea75de7b44a731ec054fbc23a91e923 SHA-1: 8995ab9f943124610a05a143aa69fac60f26e894 SHA-256: 2fd11acc5dffc9bd3cf462520bbdc305a687ba91a7a47cbefda0a5991ebf5e72
182 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, routes users through malicious redirector infrastructure and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9796

Heuristics 6

  • 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.
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • PDF links to a 'free generator / game hack' redirector high 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.
  • 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.tw/app/431946152/advexplore-free-robux-game-hack PDF link annotation
    • http://repository.ummy.ac.id//repository/free-roblox-accounts-with-robux-that-work-2021_GM431946152.pdfIn PDF document text
    • http://repository.ummy.ac.id//repository/roblox-robux_GM431946152.pdfIn PDF document text
    • http://repository.ummy.ac.id//repository/free-roblox-accounts-with-robux-that-work-not-banned_GM431946152.pdfIn PDF document text
    • http://repository.ummy.ac.id//repository/how-do-we-get-free-robux_GM431946152.pdfIn PDF document text
    • http://repository.ummy.ac.id//repository/how-to-hack-and-get-free-robux_GM431946152.pdfIn PDF document text
    • http://repository.ummy.ac.id/repository/free-robux-codes-in-roblox_GM431946152.pdfIn PDF document text
    • http://repository.ummy.ac.id/repository/marshmello-roblox-t-shirt-free_GM431946152.pdfIn PDF document text
    • http://repository.ummy.ac.id//repository/coin-master-15-free-spin-link-of-last-5-days_GM406889139.pdfIn PDF document text
    • http://repository.ummy.ac.id//repository/daily-free-spins-on-coin-master_GM406889139.pdfIn PDF document text
    • http://repository.ummy.ac.id//repository/minecraft-games-online-free-no-download_GM479516143.pdfIn PDF document text
    • http://repository.ummy.ac.id//repository/freespinandcoinblogspotcom-2021-11-coinmasterfreespinandcoinlinkshtml_GM406889139.pdfIn PDF document text
    • http://repository.ummy.ac.id/repository/1x1x1x1-in-april-fools-roblox-hacking_GM431946152.pdfIn PDF document text
    • http://repository.ummy.ac.id/repository/roblox-paintball-level-hack_GM431946152.pdfIn PDF document text
    • http://repository.ummy.ac.id//repository/roblox36com-free-robux_GM431946152.pdfIn PDF document text
    • http://repository.ummy.ac.id/repository/free-robux-no-human-verification-2021-ios_GM431946152.pdfIn PDF document text
    • http://repository.ummy.ac.id//repository/coin-master-hack-to-get-free-spins_GM406889139.pdfIn PDF document text
    • http://repository.ummy.ac.id//repository/coin-master-free-spins-for-today_GM406889139.pdfIn PDF document text
    • http://repository.ummy.ac.id/repository/roblox-redeem-codes-free-2021_GM431946152.pdfIn PDF document text
    • http://repository.ummy.ac.id/repository/roblox-trade-hack_GM431946152.pdfIn PDF document text
    • http://repository.ummy.ac.id//repository/robux-free-gift-card-org-hack_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_off000056c4.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x56C4 24772 bytes
SHA-256: 882d1746ee31851b01497c8e98ca15bb8c916cf0999293e4ea75da1b39e362a3
font_01_sfnt_off00008ffe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8FFE 2840 bytes
SHA-256: 3fb127b764b9d10f5525bc4de5ec8316de704409ccb0cf21cff3ad8a30d11676
font_02_sfnt_off000099b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x99B0 18552 bytes
SHA-256: 5b87b1308200fc22f2baf1c19d84b9969185f65dfdcff05ebdd91215d448b931

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