Malicious PDF — malware analysis report

Static analysis result for SHA-256 b757c03d443e7695…

MALICIOUS

PDF

70.2 KB Created: 2020-08-22 11:01:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e1d0363c9a2a195ce8d6334f7dff1f92 SHA-1: 257c7ae19f7d105c52ecdba8f1fca81ac896bad6 SHA-256: b757c03d443e76958ed27130f8a9048c9ad2c38966062bd0702ade5505937b63
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains a link to a known malicious redirector, ttraff.ru, which is disguised as a worksheet. The document body and embedded URLs suggest a lure to trick users into clicking the malicious link. The ML classifier strongly indicated maliciousness, and the PDF structure includes a link farm, further supporting a malicious intent.

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.ru/pify?keyword=solving+systems+of+linear+inequalities+worksheet+pdf
    • http://files.ella-day.com/uploads/1/3/0/7/130776447/nuwotusakugojesivan.pdf
    • http://files.felixschuster.org/uploads/1/3/0/8/130873838/nofisofejamin.pdf
    • https://cdn.shopify.com/s/files/1/0429/2273/7830/files/43250147187.pdf
    • https://cdn.shopify.com/s/files/1/0437/9970/7810/files/11693215321.pdf
    • https://cdn.shopify.com/s/files/1/0430/4361/8965/files/meaning_and_definition_of_democracy.pdf
    • https://cdn.shopify.com/s/files/1/0430/8179/3698/files/atos_administrativos_resumo_para_concurso.pdf
    • https://cdn.shopify.com/s/files/1/0435/2881/4741/files/infosys_aptitude_test_questions_and_answers.pdf
    • https://cdn.shopify.com/s/files/1/0437/9069/6597/files/voragugefavinuxo.pdf
    • https://cdn.shopify.com/s/files/1/0433/0792/5654/files/85438929622.pdf
    • https://cdn.shopify.com/s/files/1/0431/4162/8072/files/jitidavovitazetegazubez.pdf
    • https://cdn.shopify.com/s/files/1/0432/0637/7632/files/labuxagapuvepebazirefuvu.pdf
    • https://cdn.shopify.com/s/files/1/0450/6897/6291/files/york_air_cooled_chiller_catalogue.pdf
    • https://cdn.shopify.com/s/files/1/0432/4343/8244/files/gm_navigation_secret_menu.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ca93.bin
dd7b880f1c6958317b71933e3175eb4154b1281d355b69180e4ce829e506ee21
pdf-font-stream PDF embedded font (sfnt) at offset 0xCA93 2828 bytes
font_01_sfnt_off0000d48d.bin
1f03d8e38cb541d1debb612b5b1f59269683da48cd8c69cef9bbe3f1b4db9376
pdf-font-stream PDF embedded font (sfnt) at offset 0xD48D 6000 bytes
font_02_sfnt_off0000e8e1.bin
069ccdf04c17190cde47b3340a155b0fdd41e00ba0e81e276f71d93f1ca3634d
pdf-font-stream PDF embedded font (sfnt) at offset 0xE8E1 10120 bytes