Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c93d2d3a40054f5…

MALICIOUS

PDF

44.6 KB Created: 2020-08-30 18:51:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: dcf429a360240f328cc264f03ebe50c6 SHA-1: bd32830528358f8ed521599952d6ff7369268258 SHA-256: 4c93d2d3a40054f526e8c00e00dbda26dfe5dbb6c8d19ab34ceef720cb9ad43b
152 Risk Score

Malware Insights

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

The PDF document contains a high number of embedded URLs, with a critical heuristic firing indicating a malicious redirector link. The ML classifier also strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains references to the redirector URL and other PDF links, suggesting a link farm or SEO poisoning tactic to lure users to malicious sites.

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=nbcot+exam+study+guide
    • https://static.usrfiles.com/ugd/b8c837_053c0258328d466fb7a69ceb52b4bdd0.pdf
    • https://static.usrfiles.com/ugd/b8c837_e0120433f8ed46b1b7e740f4ad7a52f0.pdf
    • https://static.usrfiles.com/ugd/b8c837_1f0d6ebb48224e0291c738e83f12f25a.pdf
    • https://static.usrfiles.com/ugd/b8c837_847af44f1b3546cfb31964275fee38e1.pdf
    • https://static.usrfiles.com/ugd/ecec20_75fa9aef73404e4289c960daf02a75bd.pdf
    • https://cdn.shopify.com/s/files/1/0432/2679/2093/files/dusumesezawegupifod.pdf
    • https://static.usrfiles.com/ugd/ace02d_9283ff4b63324c69998c3dea0fde1e1d.pdf
    • https://static.usrfiles.com/ugd/ace02d_00d4137af7a047839b1feba1c9fb8fd5.pdf
    • https://static.usrfiles.com/ugd/09c3c7_9495158fec2e415bacb49674d9e4c4f6.pdf
    • https://static.usrfiles.com/ugd/1e32c2_5b2286ad906b491c88d3288e0f2c8dbc.pdf
    • https://static.usrfiles.com/ugd/b8c837_b8e4ae36c5374a73b9f1ceb5e9ffd61c.pdf
    • https://cdn.shopify.com/s/files/1/0448/4333/5837/files/belfast_city_centre_map.pdf
    • https://cdn.shopify.com/s/files/1/0428/5209/0022/files/ridinitilimezise.pdf
    • https://cdn.shopify.com/s/files/1/0434/4781/2248/files/binks_hvlp_spray_gun_manual.pdf
    • https://cdn.shopify.com/s/files/1/0431/2691/5239/files/89399897453.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_off00006faf.bin
dc19d02220245937a2c1d03e254fd891f5b6f4abed6c42fc2cc4c122be088377
pdf-font-stream PDF embedded font (sfnt) at offset 0x6FAF 5408 bytes
font_01_sfnt_off0000820b.bin
b3c89b1c46a14e497802034e5c27b7ce255160e167ed02f3f00d9a2d3bd84141
pdf-font-stream PDF embedded font (sfnt) at offset 0x820B 10468 bytes