Malicious PDF — malware analysis report

Static analysis result for SHA-256 86581e6f14d34ae0…

MALICIOUS

PDF

39.7 KB Created: 2020-08-31 00:51:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ea17aa3ddf99a85bbb22b47841a344c8 SHA-1: 7cab6428b250100ffdc6c2e66fd24389029f40da SHA-256: 86581e6f14d34ae0b6dc7bec02c4ab66c04fa56ae0e5710138b80c08b2b051c0
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded links, many of which point to PDF files hosted on static.usrfiles.com, suggesting a link farm. One prominent URL, 'https://ttraff.com/wix?keyword=organic+chemistry+klein+textbook', is flagged as a malicious redirector. The ML classifier also strongly indicated maliciousness. The document body, though heavily obfuscated, contains references to the redirector URL and other PDF links.

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=organic+chemistry+klein+textbook
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/de65f7_b366d560545a4402af8a1c8bb8555aab.pdf
    • https://static.usrfiles.com/ugd/5ed537_e3781bb8ed984d16a36e06a6803e04bc.pdf
    • https://static.usrfiles.com/ugd/09273f_61d78c5a56164341bb4e2f95206434a2.pdf
    • https://static.usrfiles.com/ugd/b8c837_d00d88f613e342daa10547b3680cecc8.pdf
    • https://static.usrfiles.com/ugd/e02969_1ee999474b6c41dc86cc2c375cfdcc0b.pdf
    • https://static.usrfiles.com/ugd/f96b02_59f0cd9ad7c440839317d3241a04209b.pdf
    • https://static.usrfiles.com/ugd/48f461_b5ee21b230a7438ea7b45cab6701ca05.pdf
    • https://static.usrfiles.com/ugd/f63f29_56db866d4ea14eb298c56cb5f1411e6e.pdf
    • https://static.usrfiles.com/ugd/b8c837_dfe1d7760b8645cd8075260c6caec18d.pdf
    • https://cdn.shopify.com/s/files/1/0431/7092/2655/files/80967148401.pdf
    • https://cdn.shopify.com/s/files/1/0430/1638/8761/files/xiburelelirolufafeso.pdf
    • https://cdn.shopify.com/s/files/1/0463/0672/1957/files/woralol.pdf
    • https://cdn.shopify.com/s/files/1/0431/4107/1016/files/jogos_para_ppsspp_android.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_off00005cff.bin
b712b056427d9854ff89e2e3d19a22d66341d8dd0b07d5aa8e4ec16ca7013155
pdf-font-stream PDF embedded font (sfnt) at offset 0x5CFF 5616 bytes
font_01_sfnt_off00006ff1.bin
6303446286981f0ad6e778b1fb5d29a29791a0d5747f91fa51bba87b5aace077
pdf-font-stream PDF embedded font (sfnt) at offset 0x6FF1 10008 bytes