Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c8552bf3ba311cc…

MALICIOUS

PDF

85.7 KB Created: 2021-09-20 00:04:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6f3b75c6c764161a3168273377de1835 SHA-1: 782236f51ae80b3345a53473f8b295fa41ccb2eb SHA-256: 5c8552bf3ba311cc7b2c7dbc898612c97d1cf15ca800bb678d110db1291f2ba6
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and a large number of external URIs, many of which are part of a link farm hosted on disposable or compromised domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or redirection to malware. The embedded JavaScript is likely used to facilitate the redirection or exploit PDF vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 7

  • 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.
  • 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://crysiq.ru/uplcv?utm_term=best+processor+for+gaming+for+android PDF link annotation
    • https://actorconseil.com/files/file/9232335714.pdfIn PDF document text
    • http://sentai.cc/data/file/20210912_041909_198.pdfIn PDF document text
    • http://nikolabartakova.cz/files/file/nugogemu.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/dd02fb8266b2d22d4a44ecd53ef293b2/botojokukewijegamuwora.pdfIn PDF document text
    • http://eptesteplelek.com/uploads/file/zivodifedefexasofuzapi.pdfIn PDF document text
    • http://bayernglobal.de/userVZ/file/31115354711.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1613a67865b652---69801400141.pdfIn PDF document text
    • https://ijtm.in/userfiles/file/19686396863.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613b0e532a89c---58437740247.pdfIn PDF document text
    • https://muzpony.de/obrazki/file/45010963889.pdfIn PDF document text
    • http://instalace-charvat.cz/userfiles/file/kagejataboxezep.pdfIn PDF document text
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/6p01hurjsmjted8mp1muu53pml/devofatebelovesi.pdfIn PDF document text
    • https://gs-hemeringen.de/ablage/userfiles/files/fogovilusopili.pdfIn PDF document text
    • https://hostsolutions.ro/app/webroot/files/userfiles/files/22678961408.pdfIn PDF document text
    • http://kingsauto-bar.com/js/upload/files/91668213668.pdfIn PDF document text
    • http://tuyothuyluc.vn/webroot/img/files/67408605544.pdfIn PDF document text
    • http://xedaptap.net/userfiles/file/ripasu.pdfIn PDF document text
    • http://balone.net/_upload/file///17776763913.pdfIn PDF document text
    • http://ustunongel.com/image/files/fokupituvuto.pdfIn PDF document text
    • https://pecintajp.com/contents/files/25163243448.pdfIn PDF document text
    • http://enricobarraco.com/files/towolanipadumowotub.pdfIn PDF document text
    • http://nwatchonline.org/userfiles/file/65750578840.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_off0000eca8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECA8 10968 bytes
SHA-256: 9326ed4608659f014d924e97b9e0a8096cf422d7547888020cabb9607dde7e03
font_01_sfnt_off000105f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105F4 16640 bytes
SHA-256: 3427204709d53212c70f066371938a9ed20a30f70d99861832bd0defcb740e08
font_02_sfnt_off000130f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x130F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1