Malicious PDF — malware analysis report

Static analysis result for SHA-256 997058798e3aef3c…

MALICIOUS

PDF

48.0 KB Created: 2021-06-09 05:35:55 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 6f30dfd8aa83ffad1d4a229498deca35 SHA-1: 7ca77a03d16a0344a70f3a8f34a88612f51ad218 SHA-256: 997058798e3aef3c60d0ae6e15dc59169d06091ccd0540e6568f6056a865956d
142 Risk Score

Malware Insights

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

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 5

  • 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 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/free-robux-clothes-roblox-game-hack PDF link annotation
    • https://www.astrospace.com.tw/upload/files/free-robux-no-verification-required_GM431946152.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/free-spins-from-coin-master_GM406889139.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/free-robux-working_GM431946152.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/coin-master-free-spins-link-today-new-2021_GM406889139.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/coin-master-free-spin-and-coin-link-2021-today_GM406889139.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/free-robux-that-actually-works_GM431946152.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/free-robux-giveaway-live_GM431946152.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/tiktok-free-views_GM835599320.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/coin-master-free-spin-link-twitter_GM406889139.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/coin-master-free-spins-link-2021-ios_GM406889139.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/how-to-get-free-robux-without-verification-or-surveys_GM431946152.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/free-spins-on-coin-master-generator_GM406889139.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/tiktok-minecraft-hacks_GM479516143.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/how-to-get-minecraft-bedrock-edition-for-free_GM479516143.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/free-robux-websites-that-actually-work_GM431946152.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/150-free-spins-coin-master_GM406889139.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/free-coin-coin-master_GM406889139.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/roblox-com-hack_GM431946152.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/free-spin-link-for-coin-master-game_GM406889139.pdfIn PDF document text
    • https://www.astrospace.com.tw/upload/files/free-spin-link-for-coin-master_GM406889139.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_off00005031.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x5031 27584 bytes
SHA-256: 3998e410f93df1b1818806df93a6f9052371888f437a09548a72a0466bca5961
font_01_sfnt_off00008f20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8F20 2828 bytes
SHA-256: db1860fd79a3f2cbe32e2bada3ba4c68a2d581b7a24294387cd777233cc9cef6
font_02_sfnt_off000098d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x98D7 18360 bytes
SHA-256: a1d18e52fe431c3fa184e800cbb116f4a676a51d8f231eb3c7a40e64f11ea3a2