Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c97b3cc030b6444…

MALICIOUS

PDF

39.2 KB Created: 2020-08-18 13:03:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 541c8efa75f04cc49ffcef79f3d78c73 SHA-1: 2e2db1d568c497cf528579a319af0a62786d5351 SHA-256: 7c97b3cc030b6444143aaa007d59bd697431ba332a256931f40e886ac20ada7e
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a mass of external links, many pointing to Shopify domains hosting other PDFs, and one critical link to a known malicious redirector. The document body, though partially corrupted, contains the query 'square root of 98 in decimal form' which is also present in the malicious redirector URL, suggesting a lure to a malicious site. The ML classifier 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/pify?keyword=square+root+of+98+in+decimal+form
    • http://gobarus.tanyagjewelry.com/uploads/1/3/0/7/130738850/6345719.pdf
    • http://files.dorabramden.com/uploads/1/3/1/3/131382141/3729828.pdf
    • http://files.albertacriticalcaretraining.com/uploads/1/3/0/7/130740127/ab7bc2a79e00.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0437/6385/9610/files/mozubedakid.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/98559129476.pdf
    • https://cdn.shopify.com/s/files/1/0430/4551/9513/files/guideline_pneumonia_pada_anak.pdf
    • https://cdn.shopify.com/s/files/1/0439/0558/1211/files/gexarotobid.pdf
    • https://cdn.shopify.com/s/files/1/0431/7983/5547/files/reselujusisozebaxuduxe.pdf
    • https://cdn.shopify.com/s/files/1/0433/9315/5237/files/15757191424.pdf
    • https://cdn.shopify.com/s/files/1/0431/4886/9786/files/utmost_good_faith_in_insurance_law.pdf
    • https://cdn.shopify.com/s/files/1/0433/0101/1614/files/79530330191.pdf
    • https://cdn.shopify.com/s/files/1/0433/0638/5573/files/xudufetazu.pdf
    • https://cdn.shopify.com/s/files/1/0432/1312/7835/files/57072696408.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_off000059e4.bin
b7a8bc964b38ccd3e5c4cfe6323c68fc9d50fe8e68c9365a4d0c975235226004
pdf-font-stream PDF embedded font (sfnt) at offset 0x59E4 5568 bytes
font_01_sfnt_off00006cb8.bin
8a91d7f1e5277411f24e6d2d40be4c2c1968d4dafd44f2bcd1dd2c17a9f358c8
pdf-font-stream PDF embedded font (sfnt) at offset 0x6CB8 10428 bytes