Malicious PDF — malware analysis report

Static analysis result for SHA-256 0a83b20358fc058e…

MALICIOUS

PDF

41.6 KB Created: 2020-08-30 13:45:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 14be7a0f7115d98641296e802994848b SHA-1: 346d48d877f1484868c3aa5b91c3a866e1eb2e98 SHA-256: 0a83b20358fc058e704bbbbaa9d00a55a6fd788cea64f61ae42effa1f655828f
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links, including one to a known malicious redirector, disguised as an educational worksheet. The ML classifier strongly indicated maliciousness, and the PDF structure suggests it's part of a link farm designed to drive traffic to malicious sites. While no scripts were directly extracted, the presence of embedded URLs and the heuristic firings point to a phishing or redirection scheme.

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=naming+parts+of+a+circle+worksheet
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/599f1c_4220f43adba84e609acc1f0fe8b00a3b.pdf
    • https://static.usrfiles.com/ugd/5be868_04d15150c29345e8bf0620f85407140d.pdf
    • https://static.usrfiles.com/ugd/7d1dc9_a81c397609e940f99c70b0a14faf7798.pdf
    • https://cdn.shopify.com/s/files/1/0430/4207/8877/files/80591500886.pdf
    • https://cdn.shopify.com/s/files/1/0434/7795/8816/files/76822107674.pdf
    • https://cdn.shopify.com/s/files/1/0432/5644/7136/files/10962596655.pdf
    • https://static.usrfiles.com/ugd/cb5dea_0871c73382e84ee59377989e342af736.pdf
    • https://static.usrfiles.com/ugd/a64c8c_e0c715410faa4f959f31e4dcaa3326e6.pdf
    • https://static.usrfiles.com/ugd/2c8d66_d6fa26a2f17d41ccbc41bcbaffc7c14d.pdf
    • https://static.usrfiles.com/ugd/0c41e7_f991421ea0e044f2936f4f2b94551d2f.pdf
    • https://static.usrfiles.com/ugd/b8c837_8b8174a0f62d4c7d876a8ac847d94138.pdf
    • https://static.usrfiles.com/ugd/57c819_e9d11b0c1c9a4c37a858d3e52d1ead65.pdf
    • https://static.usrfiles.com/ugd/b8c837_361361c48d774611bbb67d4743eaf568.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_off0000635e.bin
30fbe9c3679c125c8c44142b637804fca1973cd64d4415932ece4d62f35799fe
pdf-font-stream PDF embedded font (sfnt) at offset 0x635E 5556 bytes
font_01_sfnt_off0000762a.bin
2a1a7916a8a89fae4db07f50538780e7d8bed9231fc92d2b98132350a415670b
pdf-font-stream PDF embedded font (sfnt) at offset 0x762A 10364 bytes