Malicious PDF — malware analysis report

Static analysis result for SHA-256 66ae8c91b70d3325…

MALICIOUS

PDF

35.9 KB Created: 2020-08-19 13:29:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f9324453fd9b84bb8a4dde22606e1546 SHA-1: affb0fd3d4a331133305bdd0bc01e6e8daf8caab SHA-256: 66ae8c91b70d3325f0a26c8be4ea446e045dc35d62c1b1a5d73870c8c42c48a1
154 Risk Score

Malware Insights

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

The PDF contains a link that redirects to a known malicious URL, disguised as a 'conjunction worksheet for 4th grade'. The document also contains a large number of external links, many of which point to PDF files hosted on Shopify, suggesting a link farm or SEO poisoning attempt. The ML classifier strongly indicated maliciousness.

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=conjunction+worksheet+for+4th+grade
    • http://files.patersonsland.co.uk/uploads/1/3/0/8/130874238/baguzemi.pdf
    • http://files.carvoeirogcc.com/uploads/1/3/1/4/131406736/a3a2b74a.pdf
    • http://wuralur.gavanw.com/uploads/1/3/1/4/131410685/1797382.pdf
    • http://files.relationship-lab.com/uploads/1/3/1/3/131384286/lutufidonurul-laveligifu-tivag-nevegibegetow.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0432/0002/0635/files/zilokidamexezu.pdf
    • https://cdn.shopify.com/s/files/1/0432/3275/5875/files/bharat_gas_new_connection_form.pdf
    • https://cdn.shopify.com/s/files/1/0432/0778/6654/files/redemoluzomitetas.pdf
    • https://cdn.shopify.com/s/files/1/0430/2936/4885/files/bowegafazupumu.pdf
    • https://cdn.shopify.com/s/files/1/0430/0685/3269/files/pdf_file_to_jpg.pdf
    • https://cdn.shopify.com/s/files/1/0433/6828/4316/files/yung_joc-_hustlenomics.pdf
    • https://cdn.shopify.com/s/files/1/0438/6032/8608/files/wegone.pdf
    • https://cdn.shopify.com/s/files/1/0428/0070/9791/files/sikiroxuku.pdf
    • https://cdn.shopify.com/s/files/1/0435/1993/4628/files/fagoxoko.pdf
    • https://cdn.shopify.com/s/files/1/0436/4288/0160/files/65474737852.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_off00004e75.bin
467b4fdc4f626db1c22bfd7f1ed8b723ce7d395439d98568d373b0943735cf4c
pdf-font-stream PDF embedded font (sfnt) at offset 0x4E75 5476 bytes
font_01_sfnt_off0000612f.bin
2a463f29616b1ded786d4600f331287e5f6616a19054d2844010c6173ff3a74b
pdf-font-stream PDF embedded font (sfnt) at offset 0x612F 9844 bytes