Malicious PDF — malware analysis report

Static analysis result for SHA-256 c53a7bc54b27d4cc…

MALICIOUS

PDF

49.0 KB Created: 2020-08-14 00:42:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 19db2aa1ee3340cc7a3b8d82d3c4360b SHA-1: 371f6dfc52ca33a2f765cc0f80860888347f4c3e SHA-256: c53a7bc54b27d4cc9bda6ba7908a3a03a21339a1e650a8ddeb5c11abb5d52b2c
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, with one identified as a known malicious redirector. The ML classifier also flagged this PDF as malicious. The document body contains text that appears to be a lure, possibly related to a 'Yellowhammer report', and includes a URL that redirects to a malicious site. The primary attack pattern involves redirecting users to malicious infrastructure through a link farm.

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=yellowhammer+report+in+full
    • http://files.coffsharbourroofing.com/uploads/1/3/1/3/131398605/3727926.pdf
    • http://files.fablabav.com/uploads/1/3/1/6/131607810/jibasirujup.pdf
    • http://pidozaweb.amodelbuiltonfaith.org/uploads/1/3/1/0/131071157/3156078.pdf
    • https://cdn.shopify.com/s/files/1/0428/0070/9791/files/5352145004.pdf
    • https://cdn.shopify.com/s/files/1/0433/7224/9251/files/international_business_strategy_management_and_the_new_realities_download.pdf
    • https://cdn.shopify.com/s/files/1/0429/8683/2035/files/42439867946.pdf
    • https://cdn.shopify.com/s/files/1/0430/9054/2753/files/6423028096.pdf
    • https://cdn.shopify.com/s/files/1/0433/7182/3267/files/rodebukedudolimurini.pdf
    • https://cdn.shopify.com/s/files/1/0429/5829/1093/files/43600105936.pdf
    • https://cdn.shopify.com/s/files/1/0437/9725/0210/files/87327865774.pdf
    • https://cdn.shopify.com/s/files/1/0435/2288/3735/files/antibiotic_resistance_research_paper.pdf
    • https://cdn.shopify.com/s/files/1/0428/7243/8947/files/4004433216.pdf
    • https://cdn.shopify.com/s/files/1/0437/5180/0981/files/maxenomegowafurumiji.pdf
    • https://cdn.shopify.com/s/files/1/0428/7194/7423/files/99173286810.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/66083684812.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_off0000831f.bin
8290961826c1a31b31a80435bec3e946113ef1e80ee9f41fc28a05ac872de18c
pdf-font-stream PDF embedded font (sfnt) at offset 0x831F 5016 bytes
font_01_sfnt_off0000941d.bin
df2d46e015a6a93f7a6e7809fb2d08dc84f969bacfbd86af5d4b13088ada8610
pdf-font-stream PDF embedded font (sfnt) at offset 0x941D 10364 bytes