Malicious PDF — malware analysis report

Static analysis result for SHA-256 e8c3d076c3286cc7…

MALICIOUS

PDF

39.4 KB Created: 2020-08-31 09:09:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 11feeec12fef1ba5284eecb3fb1fc8e7 SHA-1: 826545aad5693c6995280f377bf5c4835f9341cf SHA-256: e8c3d076c3286cc7cef553798e2052a6acb38bfe290d1370a9ef2ff8805affad
152 Risk Score

Malware Insights

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

The PDF document is identified as malicious due to its extensive use of embedded links. The primary link, 'https://ttraff.com/wix?keyword=solving+linear+inequalities+workshee', is flagged as a known malicious redirector. The document also contains a large number of other PDF links, many hosted on static.usrfiles.com, which is indicative of a link farm designed to obscure the ultimate destination or to distribute malware. The ML classifier strongly supports the malicious verdict.

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=solving+linear+inequalities+workshee
    • https://static.usrfiles.com/ugd/516793_086cce742d4844bebd14497ae433dcc8.pdf
    • https://static.usrfiles.com/ugd/270e53_bfbd2d4ba66d4b6383248ab89b61d211.pdf
    • https://static.usrfiles.com/ugd/70a38d_a37b445ffa194bd7acb6b2b00bc20e31.pdf
    • https://static.usrfiles.com/ugd/a107db_43d24200be874a74b0b992323889d250.pdf
    • https://static.usrfiles.com/ugd/defdb4_0544e5f234864dbe93d8ff7241bac87b.pdf
    • https://static.usrfiles.com/ugd/34e21e_bb512c6737c34a7291a0d43eadaae27a.pdf
    • https://cdn.shopify.com/s/files/1/0454/3496/2088/files/92605113424.pdf
    • https://cdn.shopify.com/s/files/1/0464/8068/7272/files/elkay_water_cooler_spec_sheet.pdf
    • https://static.usrfiles.com/ugd/b8c837_29722c605d6244a189447036c365eea1.pdf
    • https://static.usrfiles.com/ugd/b8c837_591654e411f94a9eab90d94087a75b17.pdf
    • https://static.usrfiles.com/ugd/b8c837_c3432394b27c49f6849e96a7c898cee8.pdf
    • https://static.usrfiles.com/ugd/5360f8_52d26be5cf894af1b59fecd19eb8d6a8.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_off00005db4.bin
474d030310d8496e471781f3aea78b5e1b399811f933a5e0e06659cc3ff1ae8a
pdf-font-stream PDF embedded font (sfnt) at offset 0x5DB4 5392 bytes
font_01_sfnt_off00007014.bin
8eeb9699b194daf04d43d66aa7360ad60cf963f293d8f9d59f4a6232096c78b7
pdf-font-stream PDF embedded font (sfnt) at offset 0x7014 9664 bytes