Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b22370b0e7766e3…

MALICIOUS

PDF

50.0 KB Created: 2020-08-12 14:16:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d774691268273411cad3f4a1e5adbc20 SHA-1: a33e1430c5ce5cd599d0a2233569115132176677 SHA-256: 5b22370b0e7766e35e6639dfc3d15cde4b5e26a58c34edd2eb1e33cc4226aef4
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded links, many of which are designed to appear as legitimate book downloads but ultimately redirect to a known malicious URL. The ML classifier strongly indicated maliciousness, and the PDF_SEO_LINK_FARM heuristic confirms the presence of a link farm designed to manipulate search results or distribute malicious content. The primary malicious IOC is the redirector URL.

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.ru/pify?keyword=robert+bringhurst+elements+of+typographic+style+pdf
    • http://files.bartholomaeusofsalerno.org/uploads/1/3/0/7/130739232/jomis.pdf
    • http://files.podunkideas.com/uploads/1/3/0/7/130776483/fafozelaguk.pdf
    • http://files.cowboys4heroes.com/uploads/1/3/1/6/131607063/2b96a3b6ee1dce.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0429/5340/8675/files/tezewafi.pdf
    • https://cdn.shopify.com/s/files/1/0427/7967/2735/files/76776899522.pdf
    • https://cdn.shopify.com/s/files/1/0437/4567/3377/files/50717810417.pdf
    • https://cdn.shopify.com/s/files/1/0430/0147/9321/files/rejoma.pdf
    • https://cdn.shopify.com/s/files/1/0428/6146/1670/files/nepezazabilediv.pdf
    • https://cdn.shopify.com/s/files/1/0437/5311/1704/files/learn_java_8_in_21_days.pdf
    • https://cdn.shopify.com/s/files/1/0449/3144/9000/files/fury_warrior_trinkets.pdf
    • https://cdn.shopify.com/s/files/1/0434/6665/3858/files/jvc_remote_control.pdf
    • https://cdn.shopify.com/s/files/1/0440/1093/0341/files/axis_bank_savings_account_closure_form.pdf
    • https://cdn.shopify.com/s/files/1/0455/7878/0837/files/beginnings_and_beyond.pdf
    • https://cdn.shopify.com/s/files/1/0428/6870/3398/files/cyanobacteria_download.pdf
    • https://cdn.shopify.com/s/files/1/0428/7981/1750/files/nujizegefobewaxivoze.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000084c8.bin
15223036910375768fb75c71963f787589789492ba1102361ec2d6ea323b2f70
pdf-font-stream PDF embedded font (sfnt) at offset 0x84C8 5816 bytes
font_01_sfnt_off0000986c.bin
c8c8b418215c8cd0b4d8cb3ab84565a28b3b4117d45723e68a217e9f2ee644d3
pdf-font-stream PDF embedded font (sfnt) at offset 0x986C 10096 bytes