Malicious PDF — malware analysis report

Static analysis result for SHA-256 1e9d4cbe528ae858…

MALICIOUS

PDF

43.0 KB Created: 2020-08-08 17:03:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 3876ef1caa4bde91cce4301b20370870 SHA-1: 455fb1952944feff836876ca4b2ec0d8db07fbbf SHA-256: 1e9d4cbe528ae858d98e06b926703f122d617b30a99f622a8865ae5095f37f00
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a significant number of embedded links, many pointing to external PDF files hosted on various domains, including a known malicious redirector. The heuristic PDF_MALICIOUS_REDIRECTOR_LINK and PDF_SEO_LINK_FARM strongly indicate a malicious intent, likely to distribute further malware or engage in SEO spam. The ML classifier also flagged this PDF with high confidence. The document body itself is largely unreadable binary data, but it does contain the URL that triggered the redirector heuristic.

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=class%2010%20chemistry%20chapter%205%20notes%20pdf
    • http://files.lifesolutions.co.uk/uploads/1/3/1/3/131397971/72fd09.pdf
    • http://files.dragansutic.com/uploads/1/3/0/9/130969448/gapubizaziwaxum.pdf
    • http://files.acuizen.com/uploads/1/3/1/4/131483138/ditebobikopip.pdf
    • https://cdn.shopify.com/s/files/1/0431/1806/7866/files/vutupitinij.pdf
    • https://cdn.shopify.com/s/files/1/0430/9912/7957/files/23053194062.pdf
    • https://cdn.shopify.com/s/files/1/0433/5599/6328/files/27903597495.pdf
    • https://cdn.shopify.com/s/files/1/0435/2750/4024/files/kosuloxugat.pdf
    • https://cdn.shopify.com/s/files/1/0429/2637/5071/files/sagotitaka.pdf
    • https://cdn.shopify.com/s/files/1/0436/9963/4330/files/94992796363.pdf
    • https://cdn.shopify.com/s/files/1/0429/4233/3087/files/55894283494.pdf
    • https://cdn.shopify.com/s/files/1/0432/4930/3720/files/52578204486.pdf
    • https://cdn.shopify.com/s/files/1/0429/2647/3375/files/pupuduku.pdf
    • https://cdn.shopify.com/s/files/1/0433/2499/7800/files/palijogisenuzejovuveb.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/kebiwubinixakagaxirefu.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_off000062d0.bin
baa46f2b2e59432492e19bc1875b99a1fcdefdb2a2fa0ee0dccede95f4e0fb7e
pdf-font-stream PDF embedded font (sfnt) at offset 0x62D0 5720 bytes
font_01_sfnt_off0000762a.bin
a93f9f291e92e7f4e7d9905423c1906cfbe24d8376a91d276db87ada18a31b53
pdf-font-stream PDF embedded font (sfnt) at offset 0x762A 13084 bytes