Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd165599722a648e…

MALICIOUS

PDF

46.1 KB Created: 2021-06-09 14:40:38 +07:00 Authoring application: wkhtmltopdf 0.12.6 (via Qt 4.8.7)
MD5: 6561bcc43229957f8b783a753d15eff7 SHA-1: 64948e7f9868f1f51a01b13f09021d4f130e96fa SHA-256: cd165599722a648eeb418beed51d2e5faf7238b9b13e3ac07609eea476c6e281
116 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to other PDF files hosted on the IP address 183.91.70.7. This suggests a link farm or SEO spamming operation, potentially designed to host or redirect to malicious content. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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.
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • External URI info PDF_URI
    PDF contains an external URL action
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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/rare-account-free-roblox-game-hack
    • http://183.91.70.7//repository/where-pokemon-go-free-download_GM1094591345.pdf
    • http://183.91.70.7//repository/free-spin-and-coin-blogspot_GM406889139.pdf
    • http://183.91.70.7//repository/coin-master-free-spin-redeem-code_GM406889139.pdf
    • http://183.91.70.7//repository/coin-master-free-spins-app-for-iphone_GM406889139.pdf
    • http://183.91.70.7//repository/can-pubg-uc-be-hacked_GM1330123889.pdf
    • http://183.91.70.7/repository/2021-free-spins-coin-master_GM406889139.pdf
    • http://183.91.70.7//repository/getrobux-ninja_GM431946152.pdf
    • http://183.91.70.7/repository/coin-master-hacks-no-verification_GM406889139.pdf
    • http://183.91.70.7//repository/robux-come_GM431946152.pdf
    • http://183.91.70.7//repository/free-coins-and-spins-coin-master-2021_GM406889139.pdf
    • http://183.91.70.7//repository/how-to-hack-coin-master-with-game-guardian_GM406889139.pdf
    • http://183.91.70.7/repository/universal-minecraft-converter-free_GM479516143.pdf
    • http://183.91.70.7//repository/free-robux-no-verification-2021-ios_GM431946152.pdf
    • http://183.91.70.7//repository/legit-coin-master-hack-without-verification_GM406889139.pdf
    • http://183.91.70.7//repository/how-do-i-get-free-coins-on-coin-master_GM406889139.pdf
    • http://183.91.70.7//repository/coin-master-mod-apk-unlimited-spin-download-free-full-version_GM406889139.pdf
    • http://183.91.70.7//repository/coin-master-hack-version-download-ios_GM406889139.pdf
    • http://183.91.70.7/repository/what-is-exploiting-in-roblox_GM431946152.pdf
    • http://183.91.70.7/repository/free-spins-on-coin-master-iphone_GM406889139.pdf
    • http://183.91.70.7/repository/need-free-spins-for-coin-master_GM406889139.pdf
    • http://en.wikipedia.org/wiki/MIT_License

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off000052e0.bin
f88c4aabebc2249091d5d71dff4325523c4df714421d177f72a479fbbb483e34
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x52E0 28768 bytes
font_01_sfnt_off000093c6.bin
6a7c78a2b519716cd92f933a7b2d8ee0053c6575c1599556a0081b03811df3c1
pdf-font-stream PDF embedded font (sfnt) at offset 0x93C6 18420 bytes