Malicious PDF — malware analysis report

Static analysis result for SHA-256 fc72ace74ac9399e…

MALICIOUS

PDF

41.7 KB Created: 2020-08-30 06:53:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ed5fd1b59aed2858fffd9eb9b4558f5d SHA-1: 831dcd1ff9d9657033570beb393deeb6c761b17d SHA-256: fc72ace74ac9399e5db9583103cc550dee05879e28515cf84e2a4e41d0f95f02
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains a critical heuristic firing for a malicious redirector link, which is also present in the document body. This link, 'https://ttraff.cc/wix?keyword=the+day+the+crayons+quit+free+read', is designed to redirect users to malicious infrastructure. The document also exhibits characteristics of a link farm, with numerous embedded URLs pointing to static.usrfiles.com, likely for SEO manipulation to improve the ranking of the malicious redirector. The ML classifier strongly supports the malicious nature of this PDF.

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=the+day+the+crayons+quit+free+read
    • https://static.usrfiles.com/ugd/b8c837_f47ab693e40c4d2d8411d679fbc148b2.pdf
    • https://static.usrfiles.com/ugd/b80405_6b920e563eee46dfb4cfbe31993634b7.pdf
    • https://static.usrfiles.com/ugd/b8c837_9af0223be4134b44aeaca6abddd61bdf.pdf
    • https://static.usrfiles.com/ugd/b8c837_1204c86a1a0149bda8300cb317354a4b.pdf
    • https://static.usrfiles.com/ugd/a1fb72_12fde4bd31ec4a728f29c28561fa563a.pdf
    • https://static.usrfiles.com/ugd/c8a981_16418c7b8ba943f0ad19e4cd5f4eb5c8.pdf
    • https://static.usrfiles.com/ugd/764aaa_c166125bbbac451a9490b2b6da3eae27.pdf
    • https://static.usrfiles.com/ugd/865d50_bf91b8b63ebc401ea19869ce2fd23aa5.pdf
    • https://static.usrfiles.com/ugd/a4e402_19882c65d4e148ce9fea484dab992c5a.pdf
    • https://static.usrfiles.com/ugd/b8c837_e51e4b763c4d4ca480252d4b11fa2a4e.pdf
    • https://static.usrfiles.com/ugd/b8c837_f872e80152084739b4d1b42d023644cb.pdf
    • https://static.usrfiles.com/ugd/b8c837_db36a262cf0345a29e1921386e480fe3.pdf
    • https://static.usrfiles.com/ugd/8acad3_004b991bd66b45f29f09d333d946ddf3.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_off0000661a.bin
b3351236b4835a8d05ba0170e7dfbcefb512629c36a1f8d92d6499a66aceec89
pdf-font-stream PDF embedded font (sfnt) at offset 0x661A 5252 bytes
font_01_sfnt_off000077f6.bin
8558ac8e41a68d6d72b29fb21359fee20dd4c548ad883b1c66666c4829c3a610
pdf-font-stream PDF embedded font (sfnt) at offset 0x77F6 10008 bytes