Malicious PDF — malware analysis report

Static analysis result for SHA-256 6244ce9b74d92d79…

MALICIOUS

PDF

47.6 KB Created: 2020-08-03 05:48:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0881c08727064a43f7f1c94a28a0a317 SHA-1: cd2e7ecbcff3c99cd1f041c67bfd23352621ddb9 SHA-256: 6244ce9b74d92d792449d7804634271fce5f7bf1ce4a8398e3ab5c5f4a87ff5b
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a heuristic firing for linking to known malicious redirector infrastructure, specifically pointing to 'https://ttraff.com/pify?keyword=chst+study+guide+pdf'. The document body, though heavily obfuscated, contains text suggesting it is a 'chst study guide pdf'. The presence of numerous embedded links, many pointing to Shopify domains hosting other PDFs, indicates a link farm designed to obscure the malicious redirector. 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.com/pify?keyword=chst+study+guide+pdf
    • http://files.charlesinfurna.com/uploads/1/3/1/8/131856134/23583.pdf
    • http://files.alissaellisphd.com/uploads/1/3/1/4/131452827/844207.pdf
    • http://files.vintageedinburgh.com/uploads/1/3/1/4/131483361/064474de91c.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0431/5276/9192/files/jikapifezi.pdf
    • https://cdn.shopify.com/s/files/1/0434/9027/9574/files/39343864978.pdf
    • https://cdn.shopify.com/s/files/1/0431/0712/3357/files/85551636202.pdf
    • https://cdn.shopify.com/s/files/1/0429/5557/1356/files/34398710080.pdf
    • https://cdn.shopify.com/s/files/1/0431/6151/8231/files/sawubuvalul.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/73121007565.pdf
    • https://cdn.shopify.com/s/files/1/0430/9798/1082/files/91083289995.pdf
    • https://cdn.shopify.com/s/files/1/0428/2531/8563/files/82286246405.pdf
    • https://cdn.shopify.com/s/files/1/0435/1849/2824/files/eager_beaver_wood_chipper_parts.pdf
    • https://cdn.shopify.com/s/files/1/0433/4062/8136/files/20121695504.pdf
    • https://cdn.shopify.com/s/files/1/0435/2809/3856/files/20877519672.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_off00007c43.bin
c111132e9db7d7c2526006a1de321df3b6122ebbda1d6525985e7aa08330d360
pdf-font-stream PDF embedded font (sfnt) at offset 0x7C43 4972 bytes
font_01_sfnt_off00008d38.bin
58e778526154ce285edf573eb94c8da0ad431e948d60dee03b08acf641b078e0
pdf-font-stream PDF embedded font (sfnt) at offset 0x8D38 10720 bytes