Malicious PDF — malware analysis report

Static analysis result for SHA-256 18c864e28ba9fa0b…

MALICIOUS

PDF

37.9 KB Created: 2020-08-22 10:20:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 81b56cdbae8529551b2cde87f37f1572 SHA-1: 0316c1130815d400679c802fc7c14fda42d3babe SHA-256: 18c864e28ba9fa0baac8b0632c79d6dfec1be45b937574cfecb1ff576f3f6715
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, with a critical heuristic identifying a link to known malicious redirector infrastructure. The document body, though partially corrupted, contains text suggesting a lure related to 'mymaths.co.uk online homework answers', which is likely intended to trick users into clicking the malicious link. The presence of a large number of external PDF links, many pointing to Shopify, suggests a link farm or SEO manipulation tactic to obscure the malicious redirector.

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/pify?keyword=mymaths.+co.+uk+online+homework+answers
    • http://logax.ryanhayford.com/uploads/1/3/0/7/130739197/300efb.pdf
    • http://files.rachelsvineyardtucson.org/uploads/1/3/1/3/131383664/0714680.pdf
    • http://files.sustainablemaize.com/uploads/1/3/0/9/130969681/2513a3a3.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0432/0129/8594/files/molality_calculations_worksheet_answers.pdf
    • https://cdn.shopify.com/s/files/1/0428/5893/8531/files/15115662885.pdf
    • https://cdn.shopify.com/s/files/1/0430/1760/1181/files/74592236141.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/lasuzopaxikabade.pdf
    • https://cdn.shopify.com/s/files/1/0435/2134/3647/files/zogovizozeledifafa.pdf
    • https://cdn.shopify.com/s/files/1/0431/0751/6565/files/xslt_group_by.pdf
    • https://cdn.shopify.com/s/files/1/0438/7448/4379/files/translate_blogger_templates.pdf
    • https://cdn.shopify.com/s/files/1/0438/6576/8096/files/mefanevorinaw.pdf
    • https://cdn.shopify.com/s/files/1/0435/8032/6051/files/antioxidant_activity_of_centella_asiatica.pdf
    • https://cdn.shopify.com/s/files/1/0432/2381/0203/files/jogifakikeziw.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_off000056ba.bin
c78d333aed0de76cfab8a40b4094646f0fcca01a3bff958f4034f5947e1ff7c6
pdf-font-stream PDF embedded font (sfnt) at offset 0x56BA 5332 bytes
font_01_sfnt_off000068cd.bin
877a38b3fb15c9ffa9ce550bedfaec53ce8e7ab0b2ee115bb30e7109f659e3d9
pdf-font-stream PDF embedded font (sfnt) at offset 0x68CD 10024 bytes