Malicious PDF — malware analysis report

Static analysis result for SHA-256 0c5c69d310b55caf…

MALICIOUS

PDF

32.9 KB Created: 2020-08-31 03:50:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 3ff84441cc0f0aa50f28d81126d73465 SHA-1: 53dead0c0a2e8557931b337f01be0ab1cd4bffc0 SHA-256: 0c5c69d310b55caf906d93553e50bb22d64838dc57902baafebc54f2481d023f
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 external PDFs, suggesting a link farm or SEO manipulation tactic. One critical heuristic identified a link to known malicious redirector infrastructure, which is likely the primary malicious function. The ML classifier strongly supports the malicious verdict.

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=james+stewart+essential+calculus+answers
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/83b1b3_ed313b77cff9499586b84256bc25cfc7.pdf
    • https://static.usrfiles.com/ugd/b91566_f487c3d6ebc74ecc8ebb06be449fc441.pdf
    • https://static.usrfiles.com/ugd/e2c250_8e918687ec144051a2bcfdc0ca75c066.pdf
    • https://cdn.shopify.com/s/files/1/0428/8184/3356/files/jerodumutotida.pdf
    • https://cdn.shopify.com/s/files/1/0433/1828/0357/files/brgschaftserklrung_kredit.pdf
    • https://cdn.shopify.com/s/files/1/0432/8436/5476/files/romonetiziwatorawixasu.pdf
    • https://cdn.shopify.com/s/files/1/0440/9812/5976/files/23432834811.pdf
    • https://cdn.shopify.com/s/files/1/0435/3749/8271/files/birthday_cards_free_to_friend.pdf
    • https://static.usrfiles.com/ugd/3aee12_b3b72d53340b448284c8e97e7599fe7a.pdf
    • https://static.usrfiles.com/ugd/ba3095_a1c1032232e74093ad8496f6870361bf.pdf
    • https://static.usrfiles.com/ugd/4b7290_4d88d58b52114d7ebf5c5933c9557773.pdf
    • https://static.usrfiles.com/ugd/b8c837_6284ee5ef7f74cc293fa6d99cbb42d45.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_off0000444f.bin
149550f9f4d7eef5985937a3e57c17a58878a45b13dfd46139791fb8635b1d8d
pdf-font-stream PDF embedded font (sfnt) at offset 0x444F 5024 bytes
font_01_sfnt_off0000555b.bin
916f2204a8e15664c9e73854b2c1533151ecb00a84f35a7f2484f6b6df43d79e
pdf-font-stream PDF embedded font (sfnt) at offset 0x555B 10052 bytes