Malicious PDF — malware analysis report

Static analysis result for SHA-256 18bd377ed6c06fdb…

MALICIOUS

PDF

38.3 KB Created: 2020-08-14 23:24:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2026-05-09
MD5: d7d38b46d1c047706405c6e3f60636f6 SHA-1: 63127f13732a2aabcdd7a773db5fc72334e4709e SHA-256: 18bd377ed6c06fdb5b41a7e926ac1868def9c4633eb9497b9ef20aa8302235b1
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains multiple embedded links, including one pointing to a known malicious redirector infrastructure. The document body, though obfuscated, contains text related to 'math worksheets' and a URL that further supports a lure for potentially malicious content. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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/pify?keyword=math+worksheets+bar+graphs+3rd+grade In PDF document text
    • http://files.nathanbirr.com/uploads/1/3/2/7/132740378/76a563d8d5d46.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cdn.shopify.com/s/files/1/0435/1790/3008/files/6125168875.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/3346/8839/files/48484184197.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/9648/9632/files/57627721620.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/7608/4117/files/tajekovibudasumadeso.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/6499/9590/files/65869993485.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/dedijadexurusefux.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/78578063821.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/6138/7170/files/mezibolu.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005711.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x5711 5652 bytes
SHA-256: f4b9b663b7a3408ebeefa9396ed4f0a53d4500cda94cdbd5060a9e199bef52e4
font_01_sfnt_off00006a62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6A62 10168 bytes
SHA-256: b1a4f0b1b9493a6b52b549b8ad1fc9576b0c921d2f2accbe595987e20294ea7e