Malicious PDF — malware analysis report

Static analysis result for SHA-256 f88cfe5cffbc9ac3…

MALICIOUS

PDF

71.6 KB Created: 2021-09-13 23:32:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: dce6f366c187b86e02159f4661be8f53 SHA-1: 8c9441f57acc8acb917b0d8d13958e0eed439f0a SHA-256: f88cfe5cffbc9ac3c154d30a9f95d63a2911d92f18ed65066f0d0cfef6805760
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are hosted on disposable domains and configured as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is a common technique for initiating malicious actions within PDF documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • 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.
  • 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 http://cambresisemploi.fr/ckfinder/userfiles/files/59822205724.pdf In PDF document text
    • http://karaokejdi.com/ckfinder/core/connector/php/upload/files/lupulexovus.pdfIn PDF document text
    • https://vico-domrep.com/ckfinder/userfiles/files/debefogudurimuwasirubawa.pdfIn PDF document text
    • https://selispin.com/calisma2/files/uploads/zunupebebefofa.pdfIn PDF document text
    • http://radio-salsa.com/php/rs/filesupload/file/lugirowiwotuwebapoz.pdfIn PDF document text
    • https://eltonltd.ru/sites/default/files/uploads/wegabelobarimuse.pdfIn PDF document text
    • https://its-bulgaria.bg/files/file/zemojemifikidudorileje.pdfIn PDF document text
    • http://eatatrudy.com/uploads/files/88321557839.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613092410d904---88078307832.pdfIn PDF document text
    • https://lyubomiradineva.com/files/file/wemix.pdfIn PDF document text
    • http://tuyothuyluc.vn/webroot/img/files/55495240535.pdfIn PDF document text
    • http://szintai.hu/ckfinder/userfiles/files/43560441885.pdfIn PDF document text
    • http://chikatere.com/Upload/files/85851584704.pdfIn PDF document text
    • http://tuvantindat.com/uploads/2021-09-04/images/files/favabepunus.pdfIn PDF document text
    • https://universal4shipping.net/userfiles/file/55677851887.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613429e1ccdea---94416487009.pdfIn PDF document text
    • https://gjbuyerbroker.com/userfiles/file/fopiwuvi.pdfIn PDF document text
    • http://cnzhongkui.com/fckeditor/editor/filemanager/connectors/php/uploads/file/0902083066.pdfIn PDF document text
    • http://jiab.net/userData/board/file/82649080467.pdfIn PDF document text
    • http://x-mobio.com/upload/files/8990252470.pdfIn PDF document text
    • https://mimpiindahsatu.com/contents/files/88375165238.pdfIn PDF document text
    • http://jr-bang.com/uploadfiles/20210905225100.pdfIn PDF document text
    • http://mackyz7automotive.com/js/upload/files/sininododuwodarodujim.pdfIn PDF document text
    • http://reklama-v-sochi.com/ckfinder/userfiles/files/sesawul.pdfIn PDF document text
    • http://ux-school.ru/files/files/bipikopezeguru.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=hp+wifi+printer+app+for+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_off0000b9df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9DF 15524 bytes
SHA-256: 48de7998b04ed7e4958d738a73e9e6f9451a19445628c572b70a4b3f0ce553cc
font_01_sfnt_off0000e161.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE161 10356 bytes
SHA-256: a5da85d0c2bdbc478712ee596aece6bba61f8ec4b8ff28f2b73306452e95696b
font_02_sfnt_off0000f8de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8DE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1