Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbac15fcf46ba939…

MALICIOUS

PDF

44.4 KB Created: 2020-10-16 11:34:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 1849a81ed52cf373313bb51441ad0305 SHA-1: 7c49b57b295cf80b55a17fb9a3040438e43f946c SHA-256: cbac15fcf46ba9396c7378d7eb9fa9ec5d377426f2b17bfab8acb18549b60d13
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of embedded links, many of which point to known malicious redirector infrastructure or disposable hosting. The document body, though heavily obfuscated, contains text related to 'least common multiple worksheet grade 6', suggesting a lure to disguise the malicious intent. The primary attack pattern involves redirecting users to external sites, likely for further exploitation or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://ggtraff.ru/123?keyword=least+common+multiple+worksheet+grade+6 In PDF document text
    • https://cdn-cms.f-static.net/uploads/4369936/normal_5f88b0b0673e3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369920/normal_5f880ef357891.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368250/normal_5f88cca826226.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366312/normal_5f8724ea6e5c5.pdfIn PDF document text
    • https://tabuxeniki.weebly.com/uploads/1/3/2/6/132682737/zejofiwi-juzogid.pdfIn PDF document text
    • https://zuxuzesis.weebly.com/uploads/1/3/1/4/131438019/zarigi.pdfIn PDF document text
    • https://gimejexoxixaza.weebly.com/uploads/1/3/1/8/131872185/b4b3eb38b.pdfIn PDF document text
    • https://lodirunesu.weebly.com/uploads/1/3/0/8/130874391/bipip.pdfIn PDF document text
    • https://megadezatesaram.weebly.com/uploads/1/3/0/7/130776649/takewi.pdfIn PDF document text
    • https://pasuliwipo.weebly.com/uploads/1/3/1/4/131452824/7237992.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374373/normal_5f88fe43b2525.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368474/normal_5f885bb0d8683.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365555/normal_5f879b219738f.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/7111/1330/files/delonghi_coffee_maker_user_manual.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0481/6869/8007/files/14152228143.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0458/9836/7130/files/4972037145.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0458/9620/4442/files/38726010925.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/8285/8144/files/facebook_profile_template_for_students.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4adfa2c0-126f-4ee8-ae61-de2a08a7b3ac/23308152306.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/64b3b9c7-622c-4050-8188-10255c01c1b2/99250053361.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0ec1deba-4793-43aa-b775-c3798fdcf843/41890972499.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006ebc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6EBC 5736 bytes
SHA-256: 672e4071d42ff46174a94ad16835ac8c9b4518a7a94016b658014d71bb3aee58
font_01_sfnt_off00008221.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8221 9816 bytes
SHA-256: 7db28fd101477e64864a2d295ba2c151d1bd229dca2d905fb7fb37bef0c70643