Malicious PDF — malware analysis report

Static analysis result for SHA-256 c79977ae40a4947a…

MALICIOUS

PDF

76.1 KB Created: 2021-09-17 21:33:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a31e33c7eb5570d86faaa2b302575d1c SHA-1: 578f1e81d737be99784b41565faae11d4936433b SHA-256: c79977ae40a4947a9491aeda8c97468dec9976a69e826fc9669a8b181548397d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to disposable domains and are likely used for phishing or distributing further malware. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM indicates a link farm strategy, suggesting the PDF's primary purpose is to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://congtydaihai.com/upload/files/binedexufa.pdf In PDF document text
    • https://napraforgohotel.hu/upload/file/29853493619.pdfIn PDF document text
    • https://bfull.ru/uploads/files/mewejelus.pdfIn PDF document text
    • http://dichvugiayphep.net/hinhanh_fckeditor/file/namesegu.pdfIn PDF document text
    • http://onfireinteriors.com/userfiles/97018450068.pdfIn PDF document text
    • https://warungmimpishio.com/contents/files/76786428299.pdfIn PDF document text
    • https://datatech-int.com/userfiles/file/49783581130.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135a6b5250d0---namenodugixizubesozul.pdfIn PDF document text
    • https://ketdoanbus.com/webroot/img/files/xipavejusezalujoku.pdfIn PDF document text
    • http://ideal-site.ru/userfiles/file/24953474584.pdfIn PDF document text
    • http://confidenzacsapagy.hu/upload/sekijuxilal.pdfIn PDF document text
    • http://sk-uralstroy.ru/uploads/files/rojoxedasumuzixa.pdfIn PDF document text
    • http://hiroshima-teishaku.com/userfiles/file/jitavofupabugimozawiwiren.pdfIn PDF document text
    • http://golden-candies.ru/webroot/files/files/kadozowoxiravuzutiruw.pdfIn PDF document text
    • http://fresh-j.info/images/uploadedimages/file/3466853442.pdfIn PDF document text
    • http://nadiadsa.org/userfiles/file/95174771612.pdfIn PDF document text
    • http://apcmagon.com/userfiles/65228755147.pdfIn PDF document text
    • https://marwaservicecenter.com/nbloom/fckuploads/file/kisoderebujipibusakufip.pdfIn PDF document text
    • http://wxeina.com/userfiles/files/5546388651.pdfIn PDF document text
    • http://it-hair.com/userfiles/xupisepaletisizewidok.pdfIn PDF document text
    • http://abwingssuffolk2.com/uploads/files/zudilupogafozodinivapisob.pdfIn PDF document text
    • https://aldurra.ly/images-editeur/img/file/72167288366.pdfIn PDF document text
    • http://bc-arman.kz/ckfinder/userfiles/files/rirud.pdfIn PDF document text
    • http://mps-india.com/userfiles/files/fixuj.pdfIn PDF document text
    • http://geoass.eu/userfiles/files/63618053518.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=eastbound+and+down+online+freePDF 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_off0000c3ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3AE 17948 bytes
SHA-256: 86c4584bfa07554325372900a89b0d682ddb95e9285eef6caa769da6ec2ef197
font_01_sfnt_off0000f231.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF231 10656 bytes
SHA-256: c78561b19c2a3e98693c20f24980e732d9228f22b34e3278e1f6d6677e3fa460
font_02_sfnt_off00010ac8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AC8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1