Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a5ec2fd911ce034…

MALICIOUS

PDF

46.0 KB Created: 2020-08-31 04:56:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0ced154eb39f8f9a32d3a05a084a4378 SHA-1: 54488592d1a34975f5ea0d1be9f985d59f52a7a1 SHA-256: 8a5ec2fd911ce034d52aa7bf9a91af21f37a482587f052835eb1d7e5bfcab843
152 Risk Score

Malware Insights

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

The PDF document was flagged by multiple critical heuristics for containing malicious redirector links and a link farm. The ML classifier also strongly indicated maliciousness. The primary malicious URL identified is https://ttraff.ru/wix?keyword=curso+de+filosofia+do+direito+raimundo+bezerra+falc%25C3%25A3o+pdf, which is part of a link farm pointing to various PDFs hosted on static.usrfiles.com. This suggests an SEO poisoning or phishing attack.

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.ru/wix?keyword=curso+de+filosofia+do+direito+raimundo+bezerra+falc%25C3%25A3o+pdf
    • https://static.usrfiles.com/ugd/74e9cf_38c91a516b4e4a0b88cf925fee925152.pdf
    • https://static.usrfiles.com/ugd/b5472a_168a611b113a49a9910f37a3fb2133c2.pdf
    • https://static.usrfiles.com/ugd/b8c837_5671c48fa6b54474b557c66f84927911.pdf
    • https://static.usrfiles.com/ugd/9219f8_227a670623834935bf86822260bdf456.pdf
    • https://static.usrfiles.com/ugd/63022f_089ba1315a4d423986327c4f230bd353.pdf
    • https://static.usrfiles.com/ugd/455f95_7fd278099bb945c8abdcf353d8121039.pdf
    • https://static.usrfiles.com/ugd/67e251_839ae465161a4b529685957266b47e9e.pdf
    • https://static.usrfiles.com/ugd/b8c837_abd580bfb7c341bf91d6c5d42e205d88.pdf
    • https://static.usrfiles.com/ugd/b8c837_a1e595c142fe4d1aa22bfba95c315d95.pdf
    • https://static.usrfiles.com/ugd/2ca22b_90040f48264b4ec5932b71d5ac661722.pdf
    • https://cdn.shopify.com/s/files/1/0430/4309/4677/files/kufedexulisija.pdf
    • https://cdn.shopify.com/s/files/1/0432/4563/3691/files/mcdonald_s_branding_strategy.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/xuwuvedalolavotidexetugom.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/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006e72.bin
75c5404480ec73f3cef96796bb9584b9dd572628fd0b1747839382816ff53478
pdf-font-stream PDF embedded font (sfnt) at offset 0x6E72 5712 bytes
font_01_sfnt_off00008133.bin
b0991371a30c35d2ee9e89b2cc3ee4337ee5820069b760891ed1d741a2df25b3
pdf-font-stream PDF embedded font (sfnt) at offset 0x8133 12996 bytes