Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7b6c0edb1833f08…

MALICIOUS

PDF

40.3 KB Created: 2020-08-31 15:03:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e00f4679901433de95ceb543144d589e SHA-1: 509b7f17d47983cf8f2853c8b9a870041b49ea77 SHA-256: b7b6c0edb1833f089d68945ca90888155cb04e23a03b711808a52b60d4f8811b
154 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with one identified as a malicious redirector pointing to 'https://ttraff.ru/pify?keyword=grade+2+math+worksheets+free+pdf'. The document body, though heavily obfuscated, appears to contain text related to 'grade 2 math worksheets free pdf', suggesting a lure to entice users to click the malicious link. The ML classifier strongly flagged this PDF as malicious, and the presence of a link farm further supports a malicious intent.

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.ru/pify?keyword=grade+2+math+worksheets+free+pdf
    • https://static.usrfiles.com/ugd/b8c837_47e7a86fa69c4d9eb9c52e1113801517.pdf
    • https://static.usrfiles.com/ugd/599026_6e335bc1cbb14e8ab66ea0ed2664acc0.pdf
    • https://static.usrfiles.com/ugd/b8c837_0a22ce2e91b4460cbcc5799240f38e63.pdf
    • https://static.usrfiles.com/ugd/b8c837_1285a1d03aaa434186f99d8ee747aa87.pdf
    • https://static.usrfiles.com/ugd/71fd01_2dee3d0521f44caea09a3c7290a3b618.pdf
    • https://static.usrfiles.com/ugd/8acad3_ba2bdbb948a24dbaae44aae99752b663.pdf
    • https://static.usrfiles.com/ugd/b8c837_4ed6f6ed7cc54df5bfc99d64364d70cb.pdf
    • https://static.usrfiles.com/ugd/3fc21f_2a297d5c6018424b9a71a00b8b4083e6.pdf
    • https://static.usrfiles.com/ugd/b8c837_fcd191c090a4461fa5a54edd0783f4d9.pdf
    • https://static.usrfiles.com/ugd/b8c837_428cec0b543d4fd7a34cd88414831e33.pdf
    • https://static.usrfiles.com/ugd/1decf9_1a7173ff1b96450e8e74d1b1258f81a5.pdf
    • https://static.usrfiles.com/ugd/b8c837_0e2117e68b004dbc897498a972b48566.pdf
    • https://static.usrfiles.com/ugd/4b874d_1d82b71997ab4fc3be84046b08cc1923.pdf
    • https://static.usrfiles.com/ugd/f459ea_8c06d288956446fbae6dd5005b694721.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_off00005e22.bin
914392f129ff1aa0ee9254e599f7988662edf659f58f897f3a2f83e56b157fb2
pdf-font-stream PDF embedded font (sfnt) at offset 0x5E22 5568 bytes
font_01_sfnt_off00007103.bin
9bbab23cb1e45e9053d536872152975456ea7f54300dece0f056d46c2523cd33
pdf-font-stream PDF embedded font (sfnt) at offset 0x7103 10332 bytes