Malicious PDF — malware analysis report

Static analysis result for SHA-256 676ac500776d37b0…

MALICIOUS

PDF

73.5 KB Created: 2021-05-12 17:34:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 0487cec2e7a4d52eae0c5ff6d6b392e9 SHA-1: 52ff2d17785b692f318e7f280aec4ca950a182f5 SHA-256: 676ac500776d37b0be46f6f2f32763f72d7643d8240d67a92ff52ef07b127d2a
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains a large number of external links, many of which point to disposable domains or are used in a link farm configuration, as indicated by the PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO abuse. The embedded URL 'https://leonvi.ru/strik?utm_term=english+grammar+grade+3+worksheets' is a primary indicator of this malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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://leonvi.ru/strik?utm_term=english+grammar+grade+3+worksheets PDF link annotation
    • http://lutokororale.iblogger.org/automatic_power_transmission_system.pdfIn PDF document text
    • https://juzolafer.weebly.com/uploads/1/3/4/3/134382033/5089778.pdfIn PDF document text
    • https://kukurako.weebly.com/uploads/1/3/5/3/135321284/tenok-vawifozusi.pdfIn PDF document text
    • https://tozugijojabam.weebly.com/uploads/1/3/4/6/134640227/lajalog.pdfIn PDF document text
    • https://suxewanevot.weebly.com/uploads/1/3/4/5/134595646/rotepa.pdfIn PDF document text
    • https://wejilosadala.weebly.com/uploads/1/3/0/8/130815097/lunibaj-jesikavanix-figelemak.pdfIn PDF document text
    • https://buzijivugaza.weebly.com/uploads/1/3/4/7/134709386/e31bb1d2a476.pdfIn PDF document text
    • http://trysol.xyz/common_american_idioms_and_their_meaningssbd9x.pdfIn PDF document text
    • http://checkmycredit.info/xelabidepawatizomajia5c9.pdfIn PDF document text
    • https://zarujedoxetuj.weebly.com/uploads/1/3/4/3/134313760/5746016.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/7b6aeb59-5525-4a6c-9eb4-a3738cd83542/pafosusutete.pdfIn PDF document text
    • http://witosef.rf.gd/hypertension_treatment_guidelines_aafp.pdfIn PDF document text
    • http://magivaxinel.rf.gd/49394492672.pdfIn PDF document text
    • https://09af0a6c-c0e6-47ff-90c1-5b173435ccd1.filesusr.com/ugd/b92b66_150fe45080d3467db1a96c5f18474cc9.pdf?index=trueIn PDF document text
    • https://089130c0-62ae-4bf1-a93c-656440fe8451.filesusr.com/ugd/738632_cc69f7db0b9948a9a09270273b63f673.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/e32416d1-77a8-419a-84f5-ffac203702f1/losovumurexukiwev.pdfIn PDF document text
    • https://7043ee2c-bc2d-4d46-b82c-b0075177c1aa.filesusr.com/ugd/f862b5_f70ce1a5028c41a7a14c4c3679b60858.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/3cf68192-df44-486d-9f5b-6395a98176b0/watch_big_little_lies_season_2_online_free_canada.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d8624eec-e62a-40bd-8b5b-ebee5a72677f/bunitofonunikud.pdfIn PDF document text
    • https://f0ded7c6-1882-44c2-b580-3fd8daacf182.filesusr.com/ugd/1cd4ca_c46844e9dff2437193437cb23093334a.pdf?index=trueIn PDF document text
    • http://xalajagixoba.epizy.com/68312697399.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_off0000e211.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE211 5516 bytes
SHA-256: 627399d6556d34a614e30c1ef9cc1cc60969cdbd3166aada7263749c4728c8a6
font_01_sfnt_off0000f4b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4B9 10380 bytes
SHA-256: 4a257ca28abd9ee1f4eb6eceee4a2b66e4030b54f936b44e42acc672fb9120fc