Malicious PDF — malware analysis report

Static analysis result for SHA-256 6db35862ee8aa096…

MALICIOUS

PDF

33.3 KB Created: 2020-08-29 06:16:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 9a222e0a13378797b10bc9c62de5c904 SHA-1: 38d8725808201ecba70ff67be4f009585073f467 SHA-256: 6db35862ee8aa096ac56c7d95e946af616b0868f459999f09e64b5e2a44c5d40
154 Risk Score

Malware Insights

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

The PDF contains embedded links that redirect to malicious infrastructure, specifically a URL designed to lure users with a search query for an answer key. The ML classifier strongly indicates maliciousness. The presence of numerous external PDF links, many pointing to user-generated content sites, suggests a link farm or SEO poisoning tactic to distribute the malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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://ttraff.com/wix?keyword=grammar+explorer+2+answer+key+pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/b8c837_fd55ff76e2d7412887c5dc4db07dd133.pdf
    • https://static.usrfiles.com/ugd/b8c837_a832a50151e8428ca01710cdf281340c.pdf
    • https://static.usrfiles.com/ugd/b8c837_e0bb68d4d83846e5b867af13f4ccb777.pdf
    • https://cdn.shopify.com/s/files/1/0430/6678/5953/files/namemufa.pdf
    • https://static.usrfiles.com/ugd/b8c837_daf473557cde4217b9b9c2eee6f07215.pdf
    • https://static.usrfiles.com/ugd/b8c837_82f703b384d34b78ba881e3ff4c92b8a.pdf
    • https://static.usrfiles.com/ugd/b8c837_f535ef80b684449da6f47851167064a5.pdf
    • https://static.usrfiles.com/ugd/b8c837_fb1bd4bbfa8645509f92f3164cb8f40a.pdf
    • https://static.usrfiles.com/ugd/b8c837_01f2fd2444b2434586ba0b0969919ead.pdf
    • https://static.usrfiles.com/ugd/b8c837_43db997f8bbd4688a4bd4d783f674316.pdf
    • https://static.usrfiles.com/ugd/b8c837_e7d1ee1b78a9442ca693c84e1bd26f27.pdf
    • https://static.usrfiles.com/ugd/b8c837_84d57bfd287a4c5ab69d3ef4287faab9.pdf
    • https://static.usrfiles.com/ugd/b8c837_eea862f89f4e476b905f8d61a6bb3ff7.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000043cd.bin
db2a6c801450c53d6dca7916fd716ddf42f6d556cc26d176582555bc0e7e9be5
pdf-font-stream PDF embedded font (sfnt) at offset 0x43CD 5676 bytes
font_01_sfnt_off0000572b.bin
672fbc620f48f700ca0a7b1ca39cac899ed44ce49652b49e5fb0e51c1e232ed7
pdf-font-stream PDF embedded font (sfnt) at offset 0x572B 9876 bytes