Malicious PDF — malware analysis report

Static analysis result for SHA-256 c23531be4a7ab6cc…

MALICIOUS

PDF

43.7 KB Created: 2020-08-12 19:59:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f9009d257269a8c5595474c4d5ad9245 SHA-1: fb3accc4bcaf66014c40adff73b1ca05f37d51d6 SHA-256: c23531be4a7ab6cce465a98a95c60a231c0568c0edce1766c3f8c0e80a316077
152 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link, pointing to `https://ttraff.cc/wb?keyword=gmat%20syllabus%20pdf%20download`. This URL is likely used to redirect the user to a malicious site. The document body also contains this URL and a list of other URLs, many hosted on Shopify, which are likely part of a link farm to improve search engine ranking for deceptive content. The ML classifier also strongly flagged this PDF as malicious.

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/wb?keyword=gmat%20syllabus%20pdf%20download
    • http://files.smithliving.com/uploads/1/3/2/8/132815054/fexowakusisexu-vifatiwukero-wakuwefi.pdf
    • http://files.sgionet.com/uploads/1/3/0/8/130874413/zujojunejiguwimurob.pdf
    • http://files.travisroach.com/uploads/1/3/2/7/132710601/majujulox-mesenesofot.pdf
    • https://cdn.shopify.com/s/files/1/0432/3452/5352/files/gelopexeza.pdf
    • https://cdn.shopify.com/s/files/1/0431/1190/7488/files/2073597495.pdf
    • https://cdn.shopify.com/s/files/1/0439/0954/6136/files/vehicle_tracking_system_project_report.pdf
    • https://cdn.shopify.com/s/files/1/0434/7537/0136/files/77516300886.pdf
    • https://cdn.shopify.com/s/files/1/0432/2131/9837/files/21149113570.pdf
    • https://cdn.shopify.com/s/files/1/0430/1222/7225/files/xonizoxovujuzo.pdf
    • https://cdn.shopify.com/s/files/1/0432/3491/8568/files/87951320943.pdf
    • https://cdn.shopify.com/s/files/1/0431/4392/1820/files/gobamojemabusamilukali.pdf
    • https://cdn.shopify.com/s/files/1/0437/8699/3816/files/tipos_de_fibras_textiles.pdf
    • https://cdn.shopify.com/s/files/1/0431/2409/7175/files/53467087852.pdf
    • https://cdn.shopify.com/s/files/1/0436/7004/4825/files/descriptive_paragraph_about_a_place.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_off00006c02.bin
1b829ec55de8cb0b50eb07199af8d2b5d955bfceaa1bba9dd1aaee4202b3bfc3
pdf-font-stream PDF embedded font (sfnt) at offset 0x6C02 5456 bytes
font_01_sfnt_off00007e9a.bin
243b3a4a7d0c133ad111f11de758c4024d109434e0c356e59858c0500695d7db
pdf-font-stream PDF embedded font (sfnt) at offset 0x7E9A 10488 bytes