Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8fe32f5601b52c6…

MALICIOUS

PDF

45.7 KB Created: 2020-08-30 08:06:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f77fdacfbd61589872a9f3ccd1626985 SHA-1: def2858a1c2587b309154d93364815d73f8860c0 SHA-256: c8fe32f5601b52c632cb857f733e2fc302e44802f4b996ed625a8d1b824e1d47
152 Risk Score

Malware Insights

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

The PDF was flagged as malicious by a machine learning classifier and contains a critical heuristic indicating it links to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains the primary malicious URL. The presence of a large number of external PDF links, many pointing to `static.usrfiles.com`, suggests a link farm intended to obscure the ultimate destination and potentially engage in SEO abuse for malicious purposes.

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=o+alienista+em+quadrinhos+resumo
    • https://static.usrfiles.com/ugd/b8c837_b54901a16fa140ae866ad1d87633440b.pdf
    • https://static.usrfiles.com/ugd/b8c837_2c5c661847a24ede85af15664830ebeb.pdf
    • https://static.usrfiles.com/ugd/e2c6c1_cb90f37337ae448c9bdd6be5841933fc.pdf
    • https://cdn.shopify.com/s/files/1/0435/0358/3384/files/mexas.pdf
    • https://cdn.shopify.com/s/files/1/0427/6404/2396/files/10516899614.pdf
    • https://static.usrfiles.com/ugd/b8c837_c60a33eac6584991969a75197cdb0190.pdf
    • https://static.usrfiles.com/ugd/f1780b_aecbf88a9df64ccea496d1da0aa60306.pdf
    • https://static.usrfiles.com/ugd/40b9e6_b80f4dc3faf142afb9df1a0974a9272c.pdf
    • https://static.usrfiles.com/ugd/b8c837_0a498d95f1c549b0a84515fce544a631.pdf
    • https://static.usrfiles.com/ugd/de3d83_5abb8288f5cf4884b17bea6c699c70a7.pdf
    • https://cdn.shopify.com/s/files/1/0436/9242/5384/files/essential_university_physics_2nd_edition.pdf
    • https://cdn.shopify.com/s/files/1/0432/6552/3862/files/admiralty_charts_catalogue.pdf
    • https://cdn.shopify.com/s/files/1/0431/9599/0175/files/rijaruwewudajabafeve.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_off0000737e.bin
72485baae3f63baa96f6ad6b7e85f9899d8c17730b16b7968f435e68c6b91eb6
pdf-font-stream PDF embedded font (sfnt) at offset 0x737E 5220 bytes
font_01_sfnt_off0000850a.bin
9f0b76aa091312def120abd807ae1a3cb47e08bba757384c16e0b659350512ab
pdf-font-stream PDF embedded font (sfnt) at offset 0x850A 12296 bytes