Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef8331a19937f06b…

MALICIOUS

PDF

88.3 KB Created: 2021-09-09 14:20:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 41d53b13105802c3955d2d6db2f6bb30 SHA-1: 56cfd2e80a397627181951500ae9502a41ab9b6e SHA-256: ef8331a19937f06ba383fa54a1501f367ffb542479ec8df575785cd139303e50
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and ML classifiers, indicating a high likelihood of malicious intent. The embedded JavaScript stream and the presence of a link farm pointing to compromised WordPress uploads and other disposable hosting suggest it is designed to redirect users to malicious content. The primary purpose appears to be facilitating the delivery of further malicious payloads or phishing content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://almuhja.ps/ckfinder/userfiles/files/bikox.pdf In PDF document text
    • http://ck-buhgalter.ru/userfiles/file/92976958178.pdfIn PDF document text
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/a78760f1f438e4cf87f76e36d4238edf/pamibuzuxoxegoriziga.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb2e232ddf---tepuxejedoli.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613646375c1e3---megaxote.pdfIn PDF document text
    • https://planet-pvc.com/upload/files/67455500214.pdfIn PDF document text
    • http://liceoadultos.juniorcollege.cl/userfiles/files/77210874634.pdfIn PDF document text
    • https://gad-elhak.com/userfiles/file/40702113363.pdfIn PDF document text
    • http://sudeoksa.org/userfiles/file/20210901082720.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16138dfa7ab683---2371071754.pdfIn PDF document text
    • http://air-ned.com/uploads/files/7284214434.pdfIn PDF document text
    • http://toroisg.com/public/images/files/wibulu.pdfIn PDF document text
    • https://oykufestivali.com/ckfinder/userfiles/files/fufadiro.pdfIn PDF document text
    • https://hirurgija.me/files/metazojeluvowavidapuworab.pdfIn PDF document text
    • http://pieseclimaauto.com/files/file/49117356814.pdfIn PDF document text
    • https://aykutemlak.com/upload/ckfinder/files/tigifivejodat.pdfIn PDF document text
    • http://dailyxedayhang.com/userfiles/files/68413591535.pdfIn PDF document text
    • http://carshopm.com/js/upload/files/noforutumarimidumokalogo.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/vurirazakubarakukotazikej.pdfIn PDF document text
    • https://adtw1.elfjane.com/ckfinder/userfiles/files/51131051712.pdfIn PDF document text
    • https://lengthening-sldf.com/userfiles/file/49099616082.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613367456268f---53134673378.pdfIn PDF document text
    • http://smwiarus.pl/ckfinder/userfiles/files/47055138766.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=change+default+calendar+androidPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eee5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEE5 10716 bytes
SHA-256: 85fcfbec097d99bccf53f1c8a9d0639d56be181d41f4f1c5b0b17052da7756e8
font_01_sfnt_off0001073d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1073D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F4F 20036 bytes
SHA-256: bd951423733e46a54611876cae8a3c0cc7f414c9e249f8d9e06cbe872bd54e34

Open this report in the interactive analyzer, or submit your own file for analysis.