Malicious PDF — malware analysis report

Static analysis result for SHA-256 9bc0d2bc3d9db612…

MALICIOUS

PDF

44.5 KB Created: 2020-08-29 08:13:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f322371e00267dc2fc8273d748b26438 SHA-1: 49d5b8a5920946f0c98a12c3dfb342d96ae0012d SHA-256: 9bc0d2bc3d9db612a30936bd4e1ca583f51194866df5c60c86c3df8c1a6ba7ed
152 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by an ML classifier and contains a link to a known malicious redirector. It also features a link farm pointing to multiple PDFs hosted on static.usrfiles.com, suggesting an attempt to manipulate search engine results or distribute content through a large number of similar URLs. The document body contains garbled text but includes the same keyword as the malicious redirector URL, indicating a potential lure.

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=study+guide+for+pharmacology+for+nur
    • https://static.usrfiles.com/ugd/b8c837_a98497e1b8d24f86be0b459402fb4a51.pdf
    • https://static.usrfiles.com/ugd/b8c837_6faa324095fc4f1093127f55ec6fec03.pdf
    • https://static.usrfiles.com/ugd/b8c837_146b08c34cde469494a55c87ba4bcac1.pdf
    • https://static.usrfiles.com/ugd/b8c837_98354f1194a24134a6492c032af1aa61.pdf
    • https://static.usrfiles.com/ugd/b8c837_003c288ff9d343b18038989854b6a8b5.pdf
    • https://static.usrfiles.com/ugd/b8c837_86d9ae27a821481aa156e7006b923e4a.pdf
    • https://static.usrfiles.com/ugd/b8c837_cdcc88a9e53540729b17c7be104fcc79.pdf
    • https://static.usrfiles.com/ugd/b8c837_25378482c70d42fd87e2a51379d8a995.pdf
    • https://static.usrfiles.com/ugd/b8c837_59ea315c6e2249a7b59a97cd758be3dc.pdf
    • https://static.usrfiles.com/ugd/b8c837_b9f31b5c000541bf926c45ab92b548a5.pdf
    • https://static.usrfiles.com/ugd/b8c837_9317eb29db70495d88f1b505263542c1.pdf
    • https://static.usrfiles.com/ugd/b8c837_9979734c352b4e92a8f1826d6c7d9f22.pdf
    • https://static.usrfiles.com/ugd/b8c837_efc3a2a58ac94b36bb8b3bdd4e5be681.pdf
    • https://static.usrfiles.com/ugd/b8c837_cec2a0b50b054a15a341cc5fa677495b.pdf
    • https://static.usrfiles.com/ugd/b8c837_6b55a81714a74976b0b84c4e3d273943.pdf
    • https://static.usrfiles.com/ugd/b8c837_01691dad6cbc42808a6100412fca9911.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_off00006cf2.bin
72a9ddebe9ff6392e2b9e65b3275339b83a6065ee8b4148839120cf3e3d32016
pdf-font-stream PDF embedded font (sfnt) at offset 0x6CF2 5596 bytes
font_01_sfnt_off00007fdb.bin
7a62e649bbc169d52d22478240fdb4a442e0f10c9923f3ad199f0b38dd00f823
pdf-font-stream PDF embedded font (sfnt) at offset 0x7FDB 11332 bytes