Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbd11d8a328a30b9…

MALICIOUS

PDF

68.3 KB Created: 2021-02-24 21:24:01 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 80df648cf3715c0bd06a944194ea439d SHA-1: d696875a9fc252d8fa4aab7c4ae3ba6ae8d9f696 SHA-256: cbd11d8a328a30b9a6df21eff9c0bcd253261f751d33e070d5514d4f36439a9d
156 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 are hosted on dynamic DNS services or link farms, indicating a phishing or malware distribution attempt. The heuristic 'PDF_SEO_LINK_FARM' and 'CLAMAV_DETECTION' strongly suggest malicious intent, specifically phishing. The document body, though heavily obfuscated, appears to be a lure related to a vocabulary worksheet, which is a common tactic to disguise malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://druttle.ru/wix?keyword=wife+of+bath%2527s+tale+vocabulary+worksheet+answers
    • https://vilofezilo.weebly.com/uploads/1/3/0/7/130740065/xidafem_mezumiz_ruxudaxopikemo_fumumexamewetof.pdf
    • https://cdn.sqhk.co/tojofelekob/yjaDKig/asteroid_impact_effects_by_size.pdf
    • https://cdn.sqhk.co/bobavijiwoba/aJbibDK/call_of_duty_3_xbox_360_free_download.pdf
    • https://cdn.sqhk.co/dejijadu/Lejfsgh/94927385534.pdf
    • https://cdn.sqhk.co/nubokeso/ifDOaie/piwosazigoka.pdf
    • http://rivozuzeno.mywebcommunity.org/55727874147.pdf
    • https://cdn.sqhk.co/jujejorule/mhbpahc/9123724168.pdf
    • https://cdn-cms.f-static.net/uploads/4380379/normal_6015dc10270c7.pdf
    • https://sulomotosepotu.weebly.com/uploads/1/3/4/7/134744650/porepuvanenoke-mesibojo-kiwudutevekuk-wowiruxuvotazob.pdf
    • https://sowekunozo.weebly.com/uploads/1/3/5/3/135321923/xinuti.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://mowigefugitixa.epizy.com/dudegofanekax.pdf
    • http://nufufud.epizy.com/master_electrician_exam_questions_and_answers.pdf
    • http://nununad.myartsonline.com/36347856363.pdf
    • http://zevebetuj.epizy.com/59440591045.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_off0000ceec.bin
4cb484d250b0e2afe9392d04ad6dd89185fe1a346f3f3700bb97e7665fdb0155
pdf-font-stream PDF embedded font (sfnt) at offset 0xCEEC 5472 bytes
font_01_sfnt_off0000e1b4.bin
e894698cebafc0e4333707cc1c66d13cfa48d4ce94d06823007e3f627a59c922
pdf-font-stream PDF embedded font (sfnt) at offset 0xE1B4 10096 bytes