Malicious PDF — malware analysis report

Static analysis result for SHA-256 ba035a3486417ad1…

MALICIOUS

PDF

46.7 KB Created: 2020-08-31 14:07:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: de8ec564c2ad28881455df49f4e002e6 SHA-1: 63d3ff4b7d7d55cd5cd0518789169bc72b97f66e SHA-256: ba035a3486417ad13ab59b292a8219c97620b5e7145bc71fe2769b76770a5ec1
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 redirector service. The document body, though partially corrupted, contains text related to 'chapter 19 viruses and bacteria answer key' and includes the malicious URL, suggesting a lure to trick users into clicking malicious links. The ML classifier strongly flagged this PDF as malicious, and the presence of a redirector link confirms 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/wix?keyword=chapter+19+viruses+and+bacteria+answer+key
    • https://static.usrfiles.com/ugd/b8c837_b5ce2959be1140ceb0e46b680de0cc8e.pdf
    • https://static.usrfiles.com/ugd/b8c837_1eb70771c05c47339808ce0a2527449b.pdf
    • https://static.usrfiles.com/ugd/b8c837_fe0b654dd6f3450fa4922c0acb5911b7.pdf
    • https://static.usrfiles.com/ugd/b8c837_bc2a8d158dd94335a705d6c1246d6646.pdf
    • https://static.usrfiles.com/ugd/b8c837_d238e8a2d67e4e41911288f40a2d4cc3.pdf
    • https://static.usrfiles.com/ugd/73cb9e_de6ba16962b44a3e8eaa3219ba64eeb2.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/24803542318.pdf
    • https://cdn.shopify.com/s/files/1/0432/6483/5737/files/joboxuw.pdf
    • https://cdn.shopify.com/s/files/1/0431/1092/4437/files/dinilamut.pdf
    • https://static.usrfiles.com/ugd/89363e_7756ef6043c44711b0ed68dd1b7ed1a3.pdf
    • https://static.usrfiles.com/ugd/086daf_623cca52a56b461a8f49d21da6d2478c.pdf
    • https://static.usrfiles.com/ugd/0c8cc8_63ea278e11d54c3cba5781d9746b72e2.pdf
    • https://static.usrfiles.com/ugd/b8c837_a1befd1435fb456193bef9b441353e4c.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_off00007793.bin
6f641bcbef67c6074c3dc3b249b6ba5dcc6b1a352fe33899976f27f1193b88ab
pdf-font-stream PDF embedded font (sfnt) at offset 0x7793 5700 bytes
font_01_sfnt_off00008b07.bin
060d2855804b513dc031e870ef8b5d8ee393326fb529ece1864ec205219139bd
pdf-font-stream PDF embedded font (sfnt) at offset 0x8B07 10340 bytes