Malicious PDF — malware analysis report

Static analysis result for SHA-256 4487c34a781da454…

MALICIOUS

PDF

40.8 KB Created: 2020-08-06 20:57:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1228703c8e101d35e73686a532ade4cf SHA-1: 973e93aba062ccd974edd3ddbcc8c7bd17f35985 SHA-256: 4487c34a781da45422c9d02e97ff2da4113af8ddcf411feb3a11cd38f616b560
152 Risk Score

Malware Insights

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

The PDF contains a significant number of embedded links, with a critical heuristic firing indicating a link to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains a URL that appears to be part of this link farm. The ML classifier also strongly flagged this PDF as malicious. The primary attack pattern involves redirecting users through multiple layers of links, likely to a malicious site for further exploitation.

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=beginning+spanish+worksheets+pdf
    • http://files.ecovalleyconstruction.com/uploads/1/3/1/6/131606173/3b36f003751add.pdf
    • http://files.stmarysdecatur.org/uploads/1/3/0/8/130813317/6657509a4a.pdf
    • http://files.oxtapas.com/uploads/1/3/1/3/131382590/sumuv.pdf
    • http://files.dacbuildingservices.co.uk/uploads/1/3/2/6/132683267/zagelavujarip.pdf
    • https://cdn.shopify.com/s/files/1/0428/0126/6851/files/jekajoxinipuxisurorevipa.pdf
    • https://cdn.shopify.com/s/files/1/0434/1828/8285/files/56191437543.pdf
    • https://cdn.shopify.com/s/files/1/0433/9197/5580/files/5347001008.pdf
    • https://cdn.shopify.com/s/files/1/0435/9408/8616/files/alt_code_for_bullet.pdf
    • https://cdn.shopify.com/s/files/1/0432/2341/6987/files/xakikipep.pdf
    • https://cdn.shopify.com/s/files/1/0437/4773/7754/files/giuseppe_ungaretti_poemas.pdf
    • https://cdn.shopify.com/s/files/1/0430/6396/7906/files/89751755027.pdf
    • https://cdn.shopify.com/s/files/1/0434/6429/4557/files/kojevijejujalu.pdf
    • https://cdn.shopify.com/s/files/1/0433/8892/8150/files/45630314096.pdf
    • https://cdn.shopify.com/s/files/1/0438/8136/5659/files/44146044792.pdf
    • https://cdn.shopify.com/s/files/1/0428/7240/6179/files/70339633302.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_off000060af.bin
60bd642df7861b76d6ffcd47df395b985c1ec4d9f031bb117cd93fd9239a2185
pdf-font-stream PDF embedded font (sfnt) at offset 0x60AF 5476 bytes
font_01_sfnt_off00007362.bin
a047e128461f4798bf538ce350d203f2b03f27f6a799fb0fd940bdbeacb8bb63
pdf-font-stream PDF embedded font (sfnt) at offset 0x7362 10232 bytes