Malicious PDF — malware analysis report

Static analysis result for SHA-256 511c467cc2459811…

MALICIOUS

PDF

76.2 KB Created: 2021-09-17 10:44:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: dc6bf78172e730b9fe2b12ec943d9777 SHA-1: 9c2cf2f7ff75249b96d915bba79f0894ae79de95 SHA-256: 511c467cc2459811f96b7ac8b95f64e9b8a1c75067900b99ed4f63348f25221e
96 Risk Score

Malware Insights

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

The PDF contains a large number of external URIs, many of which point to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The ML classifier strongly indicated maliciousness, and the presence of multiple PDF-specific heuristics related to URI farms and compromised uploads supports this. No scripts were extracted, limiting the ability to determine specific payload delivery mechanisms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • 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://wastran.ru/uplcv?utm_term=taking+america+back+for+god+pdf PDF link annotation
    • http://3sdent.com/upload/files/kejekijin.pdfIn PDF document text
    • http://bhk-aindling.com/userfiles/files/9635197354.pdfIn PDF document text
    • http://xn--80aaa1acmiejxr6d7fg.xn--p1ai/data/files/daratelofosezabelasuf.pdfIn PDF document text
    • http://palyavalaszto.hu/teszt/upload/file/totokosipunazi.pdfIn PDF document text
    • http://odontotecnicacoop.it/userfiles/file/66955348500.pdfIn PDF document text
    • http://emilymillerlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xowedib.pdfIn PDF document text
    • http://auxerretv.com/content/public/file/55929347090.pdfIn PDF document text
    • http://www.kigimex.com.vn/ckfinder/userfiles/files/nolob.pdfIn PDF document text
    • https://aptitudeclass.com/ckfinder/userfiles/files/82166587420.pdfIn PDF document text
    • http://clinicaveterinariagoitese.it/userfiles/files/81591653231.pdfIn PDF document text
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/e5k1e60jo87bircfa1bh7ej560/14165446028.pdfIn PDF document text
    • http://www.jfac.kr/ckfinder/userfiles/files/67426472443.pdfIn PDF document text
    • http://davidhammerstein.org/userfiles/file/68827419250.pdfIn PDF document text
    • https://shindah.com/images/ckeditor_img/files/dopuwamizoluzun.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d816f7735e---fapibikekeroduvusalod.pdfIn PDF document text
    • https://khanoomhoteli.com/basefile/khanoomhotelicom/files/36127905569.pdfIn PDF document text
    • http://kajo-frings.de/userfiles/file/93470553884.pdfIn PDF document text
    • https://misbahelmudii.org/ckfinder/userfiles/files/zuxarisezunuloxujozutufij.pdfIn PDF document text
    • http://malopolskiszlakwinny.pl/upload/File/rogupixanovugozuxunosuw.pdfIn PDF document text
    • http://wooshin.kr/uploaded/file/13252761561312a3bc0bbb.pdfIn PDF document text
    • http://mjengo.org/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/32500307799.pdfIn PDF document text
    • http://osstemcardiotec.com/files/fckeditor/file/330253709613ca897f0384.pdfIn PDF document text
    • http://murito.fr/ckfinder/userfiles/files/8140471116.pdfIn PDF document text
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/161381993cd724---77649089116.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_off0000c62a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC62A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000de41.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE41 10844 bytes
SHA-256: 1bbe84e5f9e13c1d4eeecf3630e1cc9678d65ba6c54ed07b5707a448c6a60a28
font_02_sfnt_off0000f6cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6CF 17008 bytes
SHA-256: 9be963ded9b537d4745fb6c9393e1222aa1c78dc68217bd8a76e748efd748d79