Malicious PDF — malware analysis report

Static analysis result for SHA-256 d41804cea8bfe48a…

MALICIOUS

PDF

37.6 KB Created: 2020-08-29 10:04:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d398737ca5610a6cb14dff0a4863761a SHA-1: c6699afef3ed2ed8632c060a5dfb181e85fa7b54 SHA-256: d41804cea8bfe48a5cd5ab3e82a34e46c10d029ee8add1789e221bdb6d056a8a
152 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by a machine learning classifier and contains a critical heuristic indicating a link to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains a URL that matches the suspicious redirector. Additionally, the PDF contains a large number of external links, many pointing to static.usrfiles.com, which is flagged as a link farm. The primary malicious IOC is the redirector URL, which is likely used to funnel users to a malicious site.

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/wix?keyword=onetox+recalling+letra+em+ingles
    • https://static.usrfiles.com/ugd/b8c837_9fc7cd52579b4cd58e18835e14608acb.pdf
    • https://static.usrfiles.com/ugd/b8c837_c99193cc0183462995fb5114baa79c59.pdf
    • https://static.usrfiles.com/ugd/b8c837_0fa239f3bdb440fdab8ffae0ecfc174e.pdf
    • https://static.usrfiles.com/ugd/b8c837_d09a7755d81c41c5be4fe9e2f898cce6.pdf
    • https://static.usrfiles.com/ugd/b8c837_bd9a41d05c874535a650e06885ad19cf.pdf
    • https://static.usrfiles.com/ugd/b8c837_bdd1c61c72af4b8b9397ec9026c61704.pdf
    • https://static.usrfiles.com/ugd/b8c837_85da2e815a04463ca0461b7aa322d485.pdf
    • https://cdn.shopify.com/s/files/1/0467/9856/9623/files/8249895453.pdf
    • https://cdn.shopify.com/s/files/1/0435/2838/8767/files/fojixufitetuf.pdf
    • https://cdn.shopify.com/s/files/1/0455/3677/2261/files/non_current_liabilities_on_balance_sheet.pdf
    • https://cdn.shopify.com/s/files/1/0433/1172/6750/files/chinmaya_mission_bhagavad_gita_chapter_18.pdf
    • https://cdn.shopify.com/s/files/1/0431/1767/4656/files/biography_of_abraham_lincoln_in_english.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_off0000570d.bin
f7884c15f27d4f48a505288fff16b5a6753a100b7a30ac1031380e4b6b8d3a89
pdf-font-stream PDF embedded font (sfnt) at offset 0x570D 5216 bytes
font_01_sfnt_off000068b3.bin
1ab1c5e226c8b7c562bfa39dfb55b2daf7feb7f49d1d8c19ed436a734ffb9548
pdf-font-stream PDF embedded font (sfnt) at offset 0x68B3 9768 bytes