Malicious PDF — malware analysis report

Static analysis result for SHA-256 aca4626e67e4ecdc…

MALICIOUS

PDF

82.2 KB Created: 2021-09-08 23:16:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 6a4c648edab83ce22b3f139b187b81ab SHA-1: c991f86c1c6f1284898870b201261c852121816d SHA-256: aca4626e67e4ecdcf0d37f8b2231f69424d5188276c2d28f0e9e7fd9f986a2c8
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by an ML classifier as malicious. It contains a large number of embedded URLs pointing to various domains, suggesting a link farm or phishing attempt. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a non-clustered link farm on disposable hosting, further supporting the malicious intent. While no scripts were explicitly extracted, the nature of the embedded links and the ML classification strongly suggest a malicious document, likely intended to redirect users to harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 4

  • 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://wastran.ru/uplcv?utm_term=search+for+lost+android+phone PDF link annotation
    • http://systempro.kr/userData/board/file/70966521052.pdfIn PDF document text
    • http://www.octopus-quatuorvocal.com/ckfinder/userfiles/files/jeviwututuzeboduvizin.pdfIn PDF document text
    • https://casalindasbakery.com/ckfinder/userfiles/files/97955474821.pdfIn PDF document text
    • http://romento.com/uploaded_files/userfiles/files/48834556970.pdfIn PDF document text
    • https://tidurmalam2.com/contents/files/27100823831.pdfIn PDF document text
    • http://dentish.ru/ckfinder/userfiles/files/49514443043.pdfIn PDF document text
    • https://trexanh.net/upload/files/22153652130.pdfIn PDF document text
    • http://gatewayhotelbangkok.com/upfile_hotel/files/17760535098.pdfIn PDF document text
    • http://pmrs.ps/userfiles/file/39621020086.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/16136ac8670ced---87864338370.pdfIn PDF document text
    • https://hilanguage-com-tw.triangle-design.com/files/jonagake.pdfIn PDF document text
    • https://bibliotheque-des-arts.com/ckfinder/userfiles/files/daralo.pdfIn PDF document text
    • http://businessnavigator.in/ckeditor/uploads/files/58337587313.pdfIn PDF document text
    • http://toanthinh.vn/webroot/img/files/11957489987.pdfIn PDF document text
    • http://emannsltd.com/userfiles/12889825146.pdfIn PDF document text
    • http://polenes.cl/userfiles/file/96033478228.pdfIn PDF document text
    • http://avon-bratislava.sk/files/files/14016795059.pdfIn PDF document text
    • https://xn--72ca1bzcdf9cg5df4n5a8cei.com/userfiles/files/likabusemisatomeferelip.pdfIn PDF document text
    • http://drapikowski.pl/uploaded/fck_files/file/82472820993.pdfIn PDF document text
    • http://mclarenquartz.in/ci/userfiles/files/sixusokijomure.pdfIn PDF document text
    • http://logicparcel.net/uploadsEditorfile/vizifubibonuduvotosiso.pdfIn PDF document text
    • http://cathugo-catamarans.de/res/wysiwyg/file/63279785781.pdfIn PDF document text
    • http://julianowka.pl/ckfinder/userfiles/files/zumuwanovi.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/umbvlm986bdevj8tjhmdpcth9a/27680561869.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_off0000dd60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD60 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f577.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF577 10792 bytes
SHA-256: 042bca88d6d1ef6105165d639370a8bd941bcd48bdb44dd6b74d3bc12c2cb235
font_02_sfnt_off00010e31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E31 17252 bytes
SHA-256: 07bd6d6b3d86cdb0ce48f4d5b0d4136a9b3d4bbc1e58272998b0608d04ac7791