Malicious PDF — malware analysis report

Static analysis result for SHA-256 2024bbb0667eefdc…

MALICIOUS

PDF

36.5 KB Created: 2020-08-22 01:09:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cab602b96a5138890121a87cfd4ea71a SHA-1: 9e7ac820b4dbd067227cc1f4ff4ded128401c985 SHA-256: 2024bbb0667eefdc9742f50027012b61df4239efef7856fa08580cb134b43ab9
152 Risk Score

Malware Insights

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

The PDF contains a mass external link farm, with one URL pointing to a known malicious redirector. The document body, though heavily obfuscated, contains the string 'Cambridge fce use of english pdf' and the malicious URL, suggesting a lure. The presence of numerous PDF links, many hosted on Shopify, indicates an attempt to create a link farm for SEO poisoning or to distribute malicious content. The ML classifier also strongly indicated maliciousness.

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/pify?keyword=cambridge+fce+use+of+english+pdf
    • http://files.chads-w.com/uploads/1/3/1/3/131398253/9dd680a8f.pdf
    • http://rezoxor.bensonbuffstreator.com/uploads/1/3/0/7/130776167/130727.pdf
    • http://wifin.rabbitresidence.org.uk/uploads/1/3/1/4/131406717/sibezakekegipip.pdf
    • http://files.kaseimart.com/uploads/1/3/0/9/130969525/5dee16.pdf
    • https://cdn.shopify.com/s/files/1/0431/3815/4653/files/8262132220.pdf
    • https://cdn.shopify.com/s/files/1/0430/3477/1610/files/gigabyte_motherboard_manual.pdf
    • https://cdn.shopify.com/s/files/1/0431/0653/3525/files/55123891328.pdf
    • https://cdn.shopify.com/s/files/1/0437/8152/1560/files/53915640501.pdf
    • https://cdn.shopify.com/s/files/1/0438/5013/7760/files/53870503169.pdf
    • https://cdn.shopify.com/s/files/1/0433/3142/0319/files/emotional_quotient_inventory_test_free.pdf
    • https://cdn.shopify.com/s/files/1/0434/5082/6919/files/arabidopsis_thaliana_as_model_organism.pdf
    • https://cdn.shopify.com/s/files/1/0438/3932/4325/files/cycling_jersey_template.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_off0000504a.bin
b9a87f4258d8df7bd4cfeb2085697603736324696b7d783750bf28b675b3c059
pdf-font-stream PDF embedded font (sfnt) at offset 0x504A 5612 bytes
font_01_sfnt_off0000632e.bin
76fd432db47f3e3ce4f4095f6921cc2071abef1fac4fcce7c41f92c7dca25a97
pdf-font-stream PDF embedded font (sfnt) at offset 0x632E 9988 bytes