Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c92f8e50f6cdc14…

MALICIOUS

PDF

36.6 KB Created: 2020-08-29 23:43:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 21f0394ea21b92eefa1e72c348ac5fc8 SHA-1: 746f8d83fdb5aeccc6dd50db14cfcf9e9ba1a831 SHA-256: 5c92f8e50f6cdc1479aeb82b6b7a073a7005fc1f3df1079129cd376d5ba8e998
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, with a critical heuristic firing indicating it's a redirector link to known malicious infrastructure. The ML classifier also strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains a URL that matches the redirector found in the heuristics, suggesting an attempt to lure users to 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.cc/wix?keyword=feliz+navidad+sheet+music+choir
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/b8c837_f9e1d09f19614707b9afe083cfef4409.pdf
    • https://static.usrfiles.com/ugd/b8c837_b06a2d3d25fc4f509533f5b8e18b48a4.pdf
    • https://static.usrfiles.com/ugd/b8c837_24c4568d38144288a23f171b05086522.pdf
    • https://static.usrfiles.com/ugd/b8c837_01ea57b9614d43c18c39151d72285354.pdf
    • https://static.usrfiles.com/ugd/b8c837_25f721a07d224e1392216c32a96e24b1.pdf
    • https://cdn.shopify.com/s/files/1/0432/5556/2398/files/18478806090.pdf
    • https://cdn.shopify.com/s/files/1/0431/8488/1825/files/61191022204.pdf
    • https://cdn.shopify.com/s/files/1/0446/9293/0716/files/83684610054.pdf
    • https://cdn.shopify.com/s/files/1/0429/1405/4300/files/42410613325.pdf
    • https://cdn.shopify.com/s/files/1/0433/9076/3175/files/sarkar_tamil_movie_tamilrockers_isaimini.pdf
    • https://cdn.shopify.com/s/files/1/0435/5905/9615/files/certificate_of_occupancy_nyc.pdf
    • https://cdn.shopify.com/s/files/1/0436/8013/7369/files/18668677454.pdf
    • https://cdn.shopify.com/s/files/1/0428/4504/4892/files/mirewisigotajejon.pdf
    • https://static.usrfiles.com/ugd/2b3f46_4112c4175f83428d916f34b6ea7ae3e9.pdf
    • https://static.usrfiles.com/ugd/b8c837_7a23793e39214501a84623e8fb0e75d6.pdf
    • https://static.usrfiles.com/ugd/b8c837_6fbe8aa1ddb442968027325f89fc08b0.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_off00005165.bin
463d279b83f9ecda01e026574f8bdfa6c6fa6b81c3bb8e8fb606498a8dcd1f58
pdf-font-stream PDF embedded font (sfnt) at offset 0x5165 5244 bytes
font_01_sfnt_off0000631c.bin
54aea76e51df13cb07062b97b3460f4053d642b1d94a59b8f5764ace3fd58caf
pdf-font-stream PDF embedded font (sfnt) at offset 0x631C 10296 bytes