Malicious PDF — malware analysis report

Static analysis result for SHA-256 814633b9c1e17a9f…

MALICIOUS

PDF

42.2 KB Created: 2020-08-30 19:45:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e39fdc8048245013a599a126eb5f29f1 SHA-1: c4bb8114071723e556c1be16ef170272610efca1 SHA-256: 814633b9c1e17a9f4003a869e608e4dcd47c8b77bf00ad100e6ad1e8f897abb1
154 Risk Score

Malware Insights

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

The PDF contains a lure related to 'Kuk university exam date sheet ba final' and embeds a link to `https://ttraff.cc/wix?keyword=kuk+university+exam+date+sheet+ba+final`. This URL is flagged as a known malicious redirector. The PDF also contains a large number of external links, many pointing to `static.usrfiles.com`, suggesting a link farm or SEO poisoning tactic to distribute the malicious redirector. The ML classifier strongly flagged this PDF as malicious.

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=kuk+university+exam+date+sheet+ba+final
    • https://static.usrfiles.com/ugd/e42ee3_7c64df0b90e546f59a73fda8323050db.pdf
    • https://static.usrfiles.com/ugd/ba3095_62d7a82bd2524871a97b9222a024eb62.pdf
    • https://static.usrfiles.com/ugd/299074_dfc1d28b2b714180b5593199d730af36.pdf
    • https://static.usrfiles.com/ugd/b8c837_c6865350c6904ee082f0a3b299c15577.pdf
    • https://cdn.shopify.com/s/files/1/0437/2316/1768/files/php_ldap_set_option_debug.pdf
    • https://cdn.shopify.com/s/files/1/0437/4921/2309/files/97648413457.pdf
    • https://static.usrfiles.com/ugd/576447_d00f490d19c54198a40ee6346bc397fa.pdf
    • https://static.usrfiles.com/ugd/73f3b0_1b77ed92bb4a470186f2690710e51b9d.pdf
    • https://static.usrfiles.com/ugd/0adedf_7cbb43abb979405492c8e674fee91bc5.pdf
    • https://static.usrfiles.com/ugd/c20ea7_48585af7273b4511a4c02e533512b642.pdf
    • https://static.usrfiles.com/ugd/b8c837_cb47b5f1d4014dbdb96ac6e2fda0fb45.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005926.bin
5b529125c71513d9cc1922cd18937c24bac1d933e04b4ee8229e0d3292ab4ea0
pdf-font-stream PDF embedded font (sfnt) at offset 0x5926 5320 bytes
font_01_sfnt_off00006b12.bin
e3d8531d21544f92ab2f7e4d596f307d73724274f6fd0675b41bb30c7c5be275
pdf-font-stream PDF embedded font (sfnt) at offset 0x6B12 10184 bytes
font_02_sfnt_off00008db4.bin
b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c
pdf-font-stream PDF embedded font (sfnt) at offset 0x8DB4 4324 bytes