Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fec86f8b221dcb0…

MALICIOUS

PDF

74.6 KB Created: 2021-09-17 06:49:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: e3b3a43035db46c6b3321557031b0da7 SHA-1: 6dc71edb47b0d78f820f720135b0b2bd18ac42b2 SHA-256: 4fec86f8b221dcb0cfb8dd73557cc83eed17b2387ccbe412158508da179f2d53
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, embedding numerous URLs that point to various domains, many of which appear to be compromised or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically highlights this behavior, suggesting the document's purpose is to redirect users to external sites, potentially for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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 https://synerhu.ru/uplcv?utm_term=lego+batman+3+apk+data PDF link annotation
    • http://hwayinn.com/image/files/20210905_024629.pdfIn PDF document text
    • http://df-2.de/images/daten/file/xuwon.pdfIn PDF document text
    • https://vwb.mrv-educationservices.com/content_file/files/nezow.pdfIn PDF document text
    • http://diysmart.net/userfiles/file/joxibirabitegizuganone.pdfIn PDF document text
    • http://tkhomedeco.com/assets/uploads/ckedit/files/20210907192513.pdfIn PDF document text
    • https://bharatceramics.in/ckfinder/userfiles/files/bijabizetezaka.pdfIn PDF document text
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/465a2af97bd8d7418dd958dcf5f74a04/14367308115.pdfIn PDF document text
    • https://hsiaoying.com/userfiles/file/dituzon.pdfIn PDF document text
    • https://unosms.us/userfiles/file/69876965935.pdfIn PDF document text
    • https://readandenjoy.ae/userfiles/files/67086028153.pdfIn PDF document text
    • http://stroytehcentr.ru/images/file/vuvejijudapi.pdfIn PDF document text
    • http://www.scenekunstskolen-efteruddannelsen.dk/ckfinder/userfiles/files/tifewarevozufobatigotuko.pdfIn PDF document text
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/e18bacc45ed668e00f331c88918c1a85/torof.pdfIn PDF document text
    • http://elcivan.com/admin/UserFiles/file/vifarowusitarulax.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161312171aa96d---vozogarotewazamumobe.pdfIn PDF document text
    • https://maturana.cl/upload/file/vuvojepivepesalekeze.pdfIn PDF document text
    • https://pagodatalk.com/_UploadFile/Images/file/68310625128.pdfIn PDF document text
    • http://ig-einheitsloks.de/medien/file/tixalajimonowodatogobu.pdfIn PDF document text
    • http://31kouqiang.com/userfiles/file/1631321607.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/0fdf6eeac4591b41027f87f10043b315/sizumalutuxabeparamupekas.pdfIn PDF document text
    • http://antoniolescio.net/userfiles/files/70046515508.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_off0000bbd0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBD0 10688 bytes
SHA-256: 495cdf5460074023316c2b920b914fad5ac053c6a7ce6ce22d9eb09cfe412728
font_01_sfnt_off0000d3e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3E6 19620 bytes
SHA-256: 2051ac263422ac18ea1ff7d65d2b3b7b15f07652766f812de54b0e1d7d3765be
font_02_sfnt_off000104f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104F9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1