Malicious PDF — malware analysis report

Static analysis result for SHA-256 524deb8a9a5e8bac…

MALICIOUS

PDF

40.3 KB Created: 2020-08-18 21:16:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cb3faac4d03590acfb015cb2a7a83b57 SHA-1: 45dadff7df913e66bb5c5f5727a5b345dd445205 SHA-256: 524deb8a9a5e8bac58107f6213a2fae7186f09eee70a8808b68318c5d259c9aa
152 Risk Score

Malware Insights

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

The PDF contains a significant number of external links, many pointing to PDFs hosted on Shopify, indicating a potential link farm or SEO manipulation tactic. One critical heuristic identified a link to known malicious redirector infrastructure at `https://ttraff.cc/pify?keyword=corrugated+fibre+cement+sheet+fixings`. The ML classifier also strongly flagged this PDF as malicious. No scripts were extracted, and the document body is heavily obfuscated, but the primary malicious activity appears to be the distribution of malicious links.

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/pify?keyword=corrugated+fibre+cement+sheet+fixings
    • http://files.synergymhs.com/uploads/1/3/0/9/130969185/1305e6c4db5efb9.pdf
    • http://files.baybat-edtech.com/uploads/1/3/1/4/131437443/bujibefixonam_pepubudibesu_jivamun_bumajejubatexo.pdf
    • https://cdn.shopify.com/s/files/1/0427/7311/9143/files/sisujuneribefibax.pdf
    • https://cdn.shopify.com/s/files/1/0439/9346/4990/files/farox.pdf
    • https://cdn.shopify.com/s/files/1/0432/3265/7568/files/vertical_and_horizontal_line_worksheet_preschool.pdf
    • https://cdn.shopify.com/s/files/1/0431/9887/3762/files/dodinanawekof.pdf
    • https://cdn.shopify.com/s/files/1/0432/9121/3988/files/66202590389.pdf
    • https://cdn.shopify.com/s/files/1/0432/9881/6150/files/carboxymethyl_cellulose_properties.pdf
    • https://cdn.shopify.com/s/files/1/0437/5710/9402/files/27256330571.pdf
    • https://cdn.shopify.com/s/files/1/0435/2416/1704/files/the_chosen_chaim_potok_free.pdf
    • https://cdn.shopify.com/s/files/1/0439/2199/7979/files/toberagutik.pdf
    • https://cdn.shopify.com/s/files/1/0452/3651/9069/files/81862890170.pdf
    • https://cdn.shopify.com/s/files/1/0428/7512/5923/files/tofatamikarip.pdf
    • https://cdn.shopify.com/s/files/1/0431/5060/6497/files/medicamentos_hipoglucemiantes_orales.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_off00005e09.bin
52aa2977095eb3e5f97bd65f82f69d85dcfca4a2dc29e624cb43a5d910231180
pdf-font-stream PDF embedded font (sfnt) at offset 0x5E09 5516 bytes
font_01_sfnt_off000070a3.bin
23f2c2ca29aa2e79d0e99422de739a3e66c8b0df1a559352538a2e2f08bbd37d
pdf-font-stream PDF embedded font (sfnt) at offset 0x70A3 10584 bytes