Malicious PDF — malware analysis report

Static analysis result for SHA-256 81f1d53758570061…

MALICIOUS

PDF

83.4 KB Created: 2021-09-18 05:00:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 87bdc13bb5831d6506b6e68d63e5dfb2 SHA-1: 810aeb2dd46a034375e5c5acce2d602817c5a453 SHA-256: 81f1d53758570061dcbb329ac46641ede38382f7f9e942c4841ea39be5ce2f7f
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and multiple external URIs, with one specifically using 'utm_term=download+game+among+us' to entice users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to deliver a secondary payload or lead to a phishing site. The presence of embedded JS suggests an attempt to exploit PDF vulnerabilities or redirect the user.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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://allytemp.ru/uplcv?utm_term=download+game+among+us PDF link annotation
    • http://hoteldanang.vn/uploads/images/files/jugupamazapovu.pdfIn PDF document text
    • http://webcertain.ca/contentupload/fckeditorUploads/organization_/file/rejakexe.pdfIn PDF document text
    • https://proektasis.gr/admin/spaw2/uploads/files/vakukopusofozumomugas.pdfIn PDF document text
    • http://dailymaytrogiang.com/userfiles/files/gibaxi.pdfIn PDF document text
    • https://adsbudget.net/userfiles/file/punenikowafugutiwapa.pdfIn PDF document text
    • https://designmaster.in/scgtest/eec-new/codelibrary/ckeditor/ckfinder/userfiles/files/92629662368.pdfIn PDF document text
    • http://tnslib.tools/userfiles/files/livixox.pdfIn PDF document text
    • http://ilovestory.com/upload/file/jedupogo.pdfIn PDF document text
    • http://ensky-chemical.com/upload/files/67233218547.pdfIn PDF document text
    • http://ahrestygz.com/userfiles/files/20210914_023446.pdfIn PDF document text
    • http://www.ocptecnology.com/admin/uploaded/fck/file/korusenanupawemifomilebu.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/161395c3132463---18547782331.pdfIn PDF document text
    • http://oikoscoccatoarchitettura.com/userfiles/files/lusamajilawevuket.pdfIn PDF document text
    • https://condominiovillage.com/userfiles/file/57871691916.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/427b4d339eeccbefbaee88344a60529b/19637526934.pdfIn PDF document text
    • http://gniortho.com/files/Upload/file/pukizatuve.pdfIn PDF document text
    • https://fsreloading.com/userfiles/files/werezikisawekitixo.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a867e05003---945111950.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/2740999821.pdfIn PDF document text
    • http://sugarfree-gelato.com/upload/file/36515859409.pdfIn PDF document text
    • http://bursaceyizgelinlik.com/images_upload/files/nikigumov.pdfIn PDF document text
    • http://santiagoporter.com/js/ckfinder/core/connector/php/files/bikajirazesalojapovex.pdfIn PDF document text
    • http://jnnycc.org/userfiles/file/wodekivumazenopedama.pdfIn PDF document text
    • http://caratow.eu/userfiles/file/99158457204.pdfIn PDF document text
    • https://ostrichpharmaceuticals.com/userfiles/file/81698152112.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_off0000e16e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE16E 18012 bytes
SHA-256: 0c3edf1cc0d396b4680be0dad6c482b030c6ea371b4a059ce57a7c5f3f598f28
font_01_sfnt_off0001102c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1102C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012843.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12843 10488 bytes
SHA-256: 272d956b8410761ea61bbce490c95089c6a1cd21a87e3496cec82c19df293cbb