Malicious PDF — malware analysis report

Static analysis result for SHA-256 326dc3c431307cdc…

MALICIOUS

PDF

70.4 KB Created: 2021-09-24 15:20:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 17d0ddb298430ce3eb3c200114b53bfa SHA-1: d44928be248cb716d567ec2a5465feddc3f437f0 SHA-256: 326dc3c431307cdc26361b3b4213658289d5f41bc90bb4fbf0be9992a8367e95
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous external URLs, many of which are hosted on disposable domains and appear to be part of a link farm, suggesting a phishing or malware distribution scheme. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a pattern of using multiple domains with low link density to evade detection. No scripts were extracted, but the presence of many external links points to an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

Heuristics 5

  • 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.
  • 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://laborke.ru/uplcv?utm_term=best+free+painting+app+for+android PDF link annotation
    • https://shindah.com/images/ckeditor_img/files/77827951369.pdfIn PDF document text
    • https://shopinhome.com/ci/userfiles/files/63687148067.pdfIn PDF document text
    • https://balaji-technology.com/userfiles/file/77896698437.pdfIn PDF document text
    • https://listapp.in/ci/userfiles/files/58974229707.pdfIn PDF document text
    • http://mariopresto.pl/userfiles/file/tusosezuvipopozosud.pdfIn PDF document text
    • http://galenbio.com/images/upload/file/42857582959.pdfIn PDF document text
    • http://hypotekaprezamestnancov.sk/res/file/xitaxumufajexegezara.pdfIn PDF document text
    • http://triple-a.co.th/ckfinder/userfiles/files/43862470482.pdfIn PDF document text
    • http://nhactheducthammy.com/upload/files/patugobad.pdfIn PDF document text
    • http://hockjoohin.com/admin/uploads/file/xomeden.pdfIn PDF document text
    • http://fc-junajted.com/upload/datoteke/dogerizaxuxokejobo.pdfIn PDF document text
    • http://imosa.asia/uploads/files/202109082108239585.pdfIn PDF document text
    • https://teamcode.net/upload/files/pefaxemegolaju.pdfIn PDF document text
    • http://joyear.com/ckfinder/userfiles/files/63539274496.pdfIn PDF document text
    • http://greenhere.cn/upload/ckimg/files/202109162250273425.pdfIn PDF document text
    • http://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ae100912c2---bonuto.pdfIn PDF document text
    • http://goldmustang.com/files/files/96685865572.pdfIn PDF document text
    • https://0a3exp.com/upfiles/editor/files/pakolipawojibijujuxalakeg.pdfIn PDF document text
    • https://advik.net/userfiles/file/30219838220.pdfIn PDF document text
    • http://luligang.com/ckfinder/userfiles/files/40499031230.pdfIn PDF document text
    • http://alpinedelhi.com/userfiles/files/83099449816.pdfIn PDF document text
    • https://ascend.sut.ac.th/ce/2017/src/plugins/ckfinder/userfiles/files/34559233095.pdfIn PDF document text
    • http://aeklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/46057210476.pdfIn PDF document text
    • http://evergladesharvesting.com/ckfinder/userfiles/files/papez.pdfIn PDF document text
    • https://akproauto.com/nbloom/fckuploads/file/newevopevavosafozozar.pdfIn PDF document text
    • https://ibliberia.com/ckfinder/userfiles/files/70315765928.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_off0000b49a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB49A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ccb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCB1 10680 bytes
SHA-256: 3483b9d305e6d342739df6a42093f11c8db514d866458860eeecbf80566f1cb7
font_02_sfnt_off0000e519.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE519 15616 bytes
SHA-256: 1b6484ed77966c62de7f0027a153d2d2e6e2fe82b496ae36c204e25530d730eb