Malicious PDF — malware analysis report

Static analysis result for SHA-256 a33593f1b0107a85…

MALICIOUS

PDF

78.6 KB Created: 2021-09-03 08:25:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 4e5e12a453f2b24165b5acd6f07258f8 SHA-1: d50bbc4feec7433fc2822a7af1d30000b71f7a91 SHA-256: a33593f1b0107a8585e8b2c0db0f52c90f7a293d00c9fa3a193b1e3853f4abcd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the nature of the URLs and the heuristic firings point towards a malicious document, possibly leveraging embedded JavaScript for redirection or exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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
  • 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.
  • 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://drafthe.ru/uplcv?utm_term=constante+de+equilibrio+ejercicios+pdf PDF link annotation
    • https://hamayeshniroo.com/shop/file/51446870882.pdfIn PDF document text
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606daee49749f---78152253735.pdfIn PDF document text
    • http://e3edu.vn/public/ckfinder/core/connector/php/connector.phppublic/uploadsfiles/temifitesipozalegapolate.pdfIn PDF document text
    • http://abwingsva.com/uploads/files/fuxiwesef.pdfIn PDF document text
    • http://www.mediacomriccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/160826d5ca6e3a---17049923799.pdfIn PDF document text
    • http://andrenickels.de/ckfinder/userfiles/files/93098713501.pdfIn PDF document text
    • http://beiks.info/public/file/baxozar.pdfIn PDF document text
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/a567cb132466f7558686fda08a9b901d/75778866115.pdfIn PDF document text
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1609316c3204d7---zubavonoxoxogak.pdfIn PDF document text
    • https://mmrh.myagenda.cz/pictures/editor/files/jidugubetobuwa.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/160754c8c1022e---xatagiruzozum.pdfIn PDF document text
    • http://vdadanang.vn/app/webroot/assets/files/jizofezisamusakonet.pdfIn PDF document text
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/58f401362dea39478296f4385fb859f6/94243254802.pdfIn PDF document text
    • http://bjjiffy.com/upload/52642346435.pdfIn PDF document text
    • https://semineebrasov.ro/printuri-fi/files/xebulonewavifaxusoxibif.pdfIn PDF document text
    • http://abaj.cz/UserFiles/File/83548151957.pdfIn PDF document text
    • http://castrolmintabolt.hu/images/upload/file/58148085558.pdfIn PDF document text
    • http://bularz-auto.pl/images/userfiles/file/xumolut.pdfIn PDF document text
    • http://laibros.com/ckeditor/userfiles/files/basumopim.pdfIn PDF document text
    • http://lidaoxc.com/upload/files/bomutixefatebiser.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/8068658760.pdfIn PDF document text
    • https://sanxuattrucauthangkinh.com/Images_upload/files/86634019581.pdfIn PDF document text
    • http://crosswaysrecruitment.com/userfiles/file/72727383600.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://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_off0000cccd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCCD 11160 bytes
SHA-256: 49f405e815b85edf8706f113b482710af329d104e27b304d5d69c476573cc843
font_01_sfnt_off0000e68d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE68D 18240 bytes
SHA-256: be25be489d98f32b668e6b80741bc059d4d69e8eebadf2c17823129a7616d01b
font_02_sfnt_off00011491.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11491 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1