Malicious PDF — malware analysis report

Static analysis result for SHA-256 f337e23d9ca4904f…

MALICIOUS

PDF

51.7 KB Created: 2020-07-30 10:48:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2241653abb96b56a48295e28f2a8acec SHA-1: 7a5bf812b885e0b0916ca98ba5197376f962101a SHA-256: f337e23d9ca4904fc2791413fb02f4a8e3b10dc31509ead2be5f09f0a68dd9d2
154 Risk Score

Malware Insights

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

The PDF contains a malicious redirector link disguised as a search result for a technical topic. The ML classifier strongly flagged this PDF as malicious. The primary IOC is the redirector URL, which is designed to lead users to further malicious content.

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/pify?keyword=time+complexity+of+all+sorting+and+searching+algorithms+pdf
    • http://files.northernchainspecialties.com/uploads/1/3/0/7/130775215/rivuzomogiz.pdf
    • http://files.burkettbuilding.com/uploads/1/3/0/8/130874490/soralofajekanilem.pdf
    • http://files.coolcaribbeanvacations.com/uploads/1/3/0/7/130775837/c945b79.pdf
    • http://files.foreverbostons.com/uploads/1/3/1/4/131482916/lopujubavijasagu.pdf
    • https://cdn.shopify
    • https://cdn.shopify.com/s/files/1/0438/2271/0941/files/21616376960.pdf
    • https://cdn.shopify.com/s/files/1/0429/7539/5993/files/vufuvujegubajexakoz.pdf
    • https://cdn.shopify.com/s/files/1/0440/9557/0072/files/44465770897.pdf
    • https://cdn.shopify.com/s/files/1/0432/7096/3350/files/pozuzenolizudosipidinulat.pdf
    • https://cdn.shopify.com/s/files/1/0430/7625/5897/files/tuminuteniboxakege.pdf
    • https://cdn.shopify.com/s/files/1/0434/2244/9820/files/85233253519.pdf
    • https://cdn.shopify.com/s/files/1/0435/0525/4566/files/xakak.pdf
    • https://cdn.shopify.com/s/files/1/0434/1553/5774/files/gukevok.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/49816413057.pdf
    • https://cdn.shopify.com/s/files/1/0428/8380/9439/files/mulonezunakos.pdf
    • https://cdn.shopify.com/s/files/1/0427/4801/8855/files/28871027367.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_007_off0000a7bb.bin
cf14984b9870bb1f6fa8641299a7537056e41895618ba27a50753824063be083
decompressed-pdf-stream PDF FlateDecoded stream at offset 0xA7BB 17148 bytes
font_00_sfnt_off00006958.bin
35a9f648cbd3accbea04d0b922b9d90281fd1857b5fd98f2c0494f0c514f5d88
pdf-font-stream PDF embedded font (sfnt) at offset 0x6958 5476 bytes
font_01_sfnt_off00007bc9.bin
72f4e7427f510eeb7446c2dbf4ff2e2bda16c21cd096066d7cede2e8d627d5c3
pdf-font-stream PDF embedded font (sfnt) at offset 0x7BC9 13948 bytes