Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec32caae1dccf1f3…

MALICIOUS

PDF

68.9 KB Created: 2021-09-29 08:00:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1a2e5d841f88b40f30d9e011cabee619 SHA-1: ac4a5e8571c17a6432a95519338cfbf5b8f75420 SHA-256: ec32caae1dccf1f393c3e5d7c49aabe001353ba3762c309b6965d7e1879be5c7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS platforms. The embedded URLs, despite some being marked as benign, contribute to the overall malicious intent of redirecting users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://mail.me.ntou.edu.tw/ckfinder/userfiles/files/20210926_165407.pdf In PDF document text
    • http://flamefitnessstudio.com/cewit/images/file/saxolebuxatowamozij.pdfIn PDF document text
    • http://keitbg.com/images/files/fogije.pdfIn PDF document text
    • https://dukupahit.com/contents/files/nifogamop.pdfIn PDF document text
    • http://pyramidplaster.com/file_media/file_image/file/10620489087.pdfIn PDF document text
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/4f308347404ea8b30b5b787df32e7e3b/loxopaj.pdfIn PDF document text
    • https://bunian-co.com/other_files/File/jumatumez.pdfIn PDF document text
    • http://olymp-kiev.com/temp/fckeditor/file/sefamevibamuxukedi.pdfIn PDF document text
    • http://tfforming.ru/d/files/93898000393.pdfIn PDF document text
    • http://kunmobile.vn/files/uploaded/20210913/file/vuwin.pdfIn PDF document text
    • https://szalkasszorutacskok.hu/app/webroot/files/content/files/mitodizexurazilibomikepor.pdfIn PDF document text
    • https://ibexquimica.com.br/ckfinder/userfiles/files/nuxepepiturukilokexe.pdfIn PDF document text
    • http://aajude.pt/backoffice/ckfinder/userfiles/files/67685784080.pdfIn PDF document text
    • http://phannhan.vn/files/usersfiles/files/vogezapigidaxesuvekeko.pdfIn PDF document text
    • http://b40555.handyfriendship.com/upload/files/xegojajafirakulu.pdfIn PDF document text
    • http://latiendasegura.com/contable_prueba/userfiles/file/sowuzonafofelidurodiba.pdfIn PDF document text
    • https://tsafar.ir/basefile/tsafarir/files/zuzuzexoxupewinanexo.pdfIn PDF document text
    • http://designerhouse.ru/upload/files/322811529.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/4ce738260add3c93c54ec44bdb6abf34/bumodo.pdfIn PDF document text
    • https://cfbadalona.net/ckdata/files/44989511949.pdfIn PDF document text
    • http://idevicesplus.nl/app/webroot/files/userfiles/files/tusadinukosede.pdfIn PDF document text
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614097de02cb5---puzuwovegaremukibuwabewub.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=among+us+on+laptop+downloadPDF 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_off0000adec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xADEC 15668 bytes
SHA-256: b25b430f3e8ffc45332810cac4d85d59401b22515727aea49ea6817abc30ffe7
font_01_sfnt_off0000d632.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD632 10576 bytes
SHA-256: c2dc8279993c27793bdeb4bfeae0b9afa04a53d2299ce3620088ead524fa89d3
font_02_sfnt_off0000ee3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE3D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1