Malicious PDF — malware analysis report

Static analysis result for SHA-256 85f26b739d9d9a6b…

MALICIOUS

PDF

42.8 KB Created: 2020-08-13 13:52:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c60c0f7e9791508cd98dadc4432d9a22 SHA-1: 3b4d5496e358a57bd0c8f551201bce2fa8ff4624 SHA-256: 85f26b739d9d9a6ba09060b2ee589fb827ee85edb69392677a75b91b31f5b09c
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded links, many pointing to Shopify domains hosting other PDFs, and a primary link to a known malicious redirector. This indicates a link farm strategy, likely intended to obscure the ultimate destination and potentially distribute malware or lead to phishing pages. 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=ccrn%20book%20pdf
    • http://files.tasteofexcellencepdx.com/uploads/1/3/1/3/131380305/mofeko.pdf
    • http://sujududa.bpsascoutingmiramichi.com/uploads/1/3/1/4/131407164/929c92fb9b.pdf
    • http://files.herbansprawl.com/uploads/1/3/1/4/131453657/398b028.pdf
    • http://files.pipehouseplayagrande.com/uploads/1/3/1/4/131453896/lutoleginug_banonimasig.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0433/0654/9406/files/82684129544.pdf
    • https://cdn.shopify.com/s/files/1/0428/1643/8438/files/dojogezujimonomen.pdf
    • https://cdn.shopify.com/s/files/1/0434/2244/9820/files/84466635281.pdf
    • https://cdn.shopify.com/s/files/1/0446/3670/0835/files/cnc_machine_operator_resume.pdf
    • https://cdn.shopify.com/s/files/1/0431/6489/3345/files/78794636565.pdf
    • https://cdn.shopify.com/s/files/1/0435/3484/4059/files/form_g-_45_instructions.pdf
    • https://cdn.shopify.com/s/files/1/0433/9941/3921/files/xovugupijedigi.pdf
    • https://cdn.shopify.com/s/files/1/0437/9734/8514/files/enlaces_covalentes_ejercicios.pdf
    • https://cdn.shopify.com/s/files/1/0437/7011/8306/files/23915464682.pdf
    • https://cdn.shopify.com/s/files/1/0435/3772/7637/files/gejigolowogegokurisibon.pdf
    • https://cdn.shopify.com/s/files/1/0437/0199/3622/files/vigalimagitipetanuv.pdf
    • https://cdn.shopify.com/s/files/1/0432/7941/7504/files/12367385706.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_off0000695b.bin
b7deec13cc4f7f5ae396b8cf4874cf4b9a2028a36d92e9606e6dd6a0e1586cfc
pdf-font-stream PDF embedded font (sfnt) at offset 0x695B 4840 bytes
font_01_sfnt_off000079d7.bin
895843531bc81da220e3297ef2e8413f712d8f6cdd07c166c7288b2d9c3554c8
pdf-font-stream PDF embedded font (sfnt) at offset 0x79D7 10984 bytes