Malicious PDF — malware analysis report

Static analysis result for SHA-256 f55387a368ba14db…

MALICIOUS

PDF

85.5 KB Created: 2020-08-18 15:59:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f8f2fb858178eb94e16e9f620100bf76 SHA-1: e1f6577815359f19f6cb8fa763d5bec76e7f16f1 SHA-256: f55387a368ba14db2ea53c1093e118ba54ec22dcb1bbe44d3b2b5afe5385c3df
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to Shopify domains hosting other PDFs, a technique often used for SEO poisoning or link farming. One critical heuristic identified a link to a known malicious redirector, ttraff.cc, which is likely the primary malicious payload delivery mechanism. The ML classifier strongly supports the malicious nature of this PDF.

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=htn+guidelines+2018+aafp
    • http://files.digitalworkshop.com.hk/uploads/1/3/1/4/131408103/9e63e.pdf
    • http://vutoxe.mosaicchurch.org.uk/uploads/1/3/0/8/130874457/771802.pdf
    • http://files.navslaborers.org/uploads/1/3/0/8/130874012/tegasinixak-vibim.pdf
    • https://cdn.shopify.com/s/files/1/0433/1172/6750/files/sazexopab.pdf
    • https://cdn.shopify.com/s/files/1/0433/3699/0885/files/nutizu.pdf
    • https://cdn.shopify.com/s/files/1/0430/2661/2378/files/14581397191.pdf
    • https://cdn.shopify.com/s/files/1/0435/8697/7949/files/class_6_ict_book.pdf
    • https://cdn.shopify.com/s/files/1/0431/6535/2093/files/10329190183.pdf
    • https://cdn.shopify.com/s/files/1/0430/6888/3106/files/xizena.pdf
    • https://cdn.shopify.com/s/files/1/0437/7378/8321/files/23544739888.pdf
    • https://cdn.shopify.com/s/files/1/0450/5577/0776/files/bohemian_rhapsody_fingerstyle_guitar.pdf
    • https://cdn.shopify.com/s/files/1/0431/3972/7509/files/us_constitution_amendments_summary.pdf
    • https://cdn.shopify.com/s/files/1/0429/8221/1733/files/moxasapilazugogusexajena.pdf
    • https://cdn.shopify.com/s/files/1/0430/4715/7911/files/robert_bringhurst_elements_of_typographic_style.pdf
    • https://cdn.shopify.com/s/files/1/0432/8488/9758/files/fopune.pdf
    • https://cdn.shopify.com/s/files/1/0430/6727/7469/files/lexokaxenimazanu.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_off00010acf.bin
57aeb45d6aad4e15e26f9979da2e240640f44f09bc9ae5a42d9d1203b41e3d24
pdf-font-stream PDF embedded font (sfnt) at offset 0x10ACF 5592 bytes
font_01_sfnt_off00011dec.bin
8a2ec4cb252532e6bb1881fd5dc4f1ecd769587698d68ef0e407e8e4221a328a
pdf-font-stream PDF embedded font (sfnt) at offset 0x11DEC 13148 bytes