Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd51db7addf29c99…

MALICIOUS

PDF

68.8 KB Created: 2021-09-26 10:01:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 4716206e0b35fce3cd25ef1d019b61bd SHA-1: 58ba60fb19d344c143e390d2a71c6b0cafb5cfe3 SHA-256: cd51db7addf29c9974d40243740c0768e2ce378dffca87aa0452cb4e5772489a
156 Risk Score

Malware Insights

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

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

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://bestapp4u.com/admin/uploadedfiles/file/45458774443.pdf In PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/161378a13d9157---41648569748.pdfIn PDF document text
    • http://niengrangchuyensau.com/upload/contentFile/file/rupegijugaxajudumuxo.pdfIn PDF document text
    • http://safedoorsystems.com/cmsimages/file/xasip.pdfIn PDF document text
    • https://alariel.be/userfiles/file/mofokulovuvomanojukuvigid.pdfIn PDF document text
    • http://yourhealthyanswer.com/ckfinder/userfiles/files/legodoremulifuxepa.pdfIn PDF document text
    • http://polishingmarblefloor.it/userfiles/files/46565859153.pdfIn PDF document text
    • http://watch62.ru/files/files/nezobetipegatatuxi.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1613e6dc066ddb---kinowutawejeredal.pdfIn PDF document text
    • http://redactron.com/userfiles/file/88681336242.pdfIn PDF document text
    • https://www.retake.dk/ckfinder/userfiles/files/14513595324.pdfIn PDF document text
    • http://abwlanham.com/uploads/files/kariwobebi.pdfIn PDF document text
    • http://alothongtin.com/upload/FCK/file/zibijagilozamewas.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/a2dc6c2e85f1e705f8143dc77ce83a90/xizagefoposun.pdfIn PDF document text
    • http://ongxoanhdpe.vn/upload/files/61359304156.pdfIn PDF document text
    • http://tvoirostov.ru/ckfinder/userfiles/files/95602245233.pdfIn PDF document text
    • http://manhchenang.vn/webroot/img/files/gurebozimi.pdfIn PDF document text
    • http://aunay-sous-auneau.fr/ckfinder/userfiles/files/rukijalonubenar.pdfIn PDF document text
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202109170256393643.pdfIn PDF document text
    • http://landonintergroup.com/ckfinder/userfiles/files/66088978862.pdfIn PDF document text
    • http://zhengfutz.com/v15/Upload/file/202197933409908.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/e9baac3268f39d7de62ff4b5c4534819/15130808394.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=nfs+most+wanted+cracked+apkPDF 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_off0000b004.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB004 10796 bytes
SHA-256: bb035115497b2a5dcc00f0af2d837d6c84a823bef2d8989939d3f30e7c86da76
font_01_sfnt_off0000c8f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8F9 14604 bytes
SHA-256: cd2ec80613b15eef0218e34b1afe2ffac15188f18b300c5ac9199508cbfbf0f4
font_02_sfnt_off0000ed95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED95 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1