Malicious PDF — malware analysis report

Static analysis result for SHA-256 8164939d8829ebb2…

MALICIOUS

PDF

40.6 KB Created: 2020-08-29 12:42:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: deb8aa9098e5f0ca5414a6337d7c1681 SHA-1: 1b2d0a8679e8082fad1079bc10f5ea19f692c6fa SHA-256: 8164939d8829ebb24f10a0d4d6f03bc90e2a8e91220da2c61bd8fb3dbd165b9d
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to a link farm designed to redirect users. The primary redirector URL is https://ttraff.cc/wix, which is flagged as malicious. The document body, though heavily obfuscated, contains this malicious URL and several other benign-looking URLs hosted on Shopify and static.usrfiles.com, likely as part of the link farm strategy. The ML classifier strongly indicates maliciousness.

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=introduction+to+polymers+third+edition+pdf
    • https://cdn.shopify.com/s/files/1/0440/4841/6933/files/21075114228.pdf
    • https://cdn.shopify.com/s/files/1/0439/2619/2283/files/math_worksheets_grade_2_shapes.pdf
    • https://cdn.shopify.com/s/files/1/0431/3333/7768/files/xadozemeratozuvamux.pdf
    • https://cdn.shopify.com/s/files/1/0460/3143/7983/files/xarobuturobiwe.pdf
    • https://static.usrfiles.com/ugd/ba3095_76abff16e6744cca8ee07564a3c4bb4c.pdf
    • https://static.usrfiles.com/ugd/b8c837_f3688d69465f4086acd3acd9e7f4a155.pdf
    • https://static.usrfiles.com/ugd/b8c837_b2dc94cbac1740c5a09c1362aa8ed58d.pdf
    • https://static.usrfiles.com/ugd/b8c837_bed65fcd91c445d79940ca66078fefe7.pdf
    • https://static.usrfiles.com/ugd/b8c837_c90be221867b471ab1ce3eec6149f1c0.pdf
    • https://static.usrfiles.com/ugd/b8c837_3a157940a3f544febec2083513d0072b.pdf
    • https://static.usrfiles.com/ugd/b8c837_dd3e25d7631a44d99af8c9a5ed94781c.pdf
    • https://static.usrfiles.com/ugd/b8c837_7e14e11f8f12494caa97b635a78dc641.pdf
    • https://static.usrfiles.com/ugd/b8c837_a9c5e2d08c574af38a1e288aa41168c6.pdf
    • https://static.usrfiles.com/ugd/b8c837_7a97b535424944388ee9c23b16124b08.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_off00006111.bin
cbf61e0d47d8233b5cd888970812ecaa1ba214323a2c208652181f5d9658fea5
pdf-font-stream PDF embedded font (sfnt) at offset 0x6111 5224 bytes
font_01_sfnt_off000072b4.bin
5dac1f6df979241343876fc792a38f09471258e4277545fa459ecb108700bd16
pdf-font-stream PDF embedded font (sfnt) at offset 0x72B4 10268 bytes