Malicious PDF — malware analysis report

Static analysis result for SHA-256 6cf28dc42af194a4…

MALICIOUS

PDF

97.0 KB Created: 2021-07-03 14:50:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 154544b9e4d35353b92cdba4ef0a427f SHA-1: e5b1965181ccf7e6cabe54ce5da736f0a0931db9 SHA-256: 6cf28dc42af194a4356661ed5ada5a143350dcd651adf9bd88eebb9017498fb0
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised or disposable domains, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for SEO manipulation or to serve as a distribution point for further malware. The document body is heavily obfuscated and does not provide direct user-facing content, but the heuristic firings clearly indicate the presence of a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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://consultingexpert.eu/fckeditor/userfiles/file/xesijidife.pdf
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087d7f280dd1---61435634758.pdf
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608aceda8563a---namekidimiv.pdf
    • https://bititechnika.com/uploads/file/11706197441.pdf
    • https://wills.sg/wp-content/plugins/super-forms/uploads/php/files/97f89bfcb29478efdfd5b13b7134896a/2612350098.pdf
    • http://naasschoolofmotoring.com/fckeditor/userfiles/file/zobomu.pdf
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/522cb443cc8dabb592bd3b9cedb29176/75318205321.pdf
    • http://graviroz.hu/ckfinder/userfiles/files/30609719396.pdf
    • http://zabradli-znerezu.cz/userfiles/file/zevidijegipetavupibo.pdf
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094417d17d26---41926939947.pdf
    • http://signexpowholesale.com/project-new/christianbook/upload_images/file/39169949523.pdf
    • http://omgmediatank.com/userfiles/files/wenipupat.pdf
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1606d17565d6c9---jukijit.pdf
    • http://veterina-hrib.cz/user-uploads/files/tututub.pdf
    • https://kompaspt1.com/contents//files/pasol.pdf
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/83086355673.pdf
    • https://fmpride.com/wp-content/plugins/super-forms/uploads/php/files/ee97bd607fddf3fc1b996517b116e1a3/67731756979.pdf
    • https://htchninc.com/d/files/2817413026.pdf
    • http://nyett.hk/uploads/news/files/sexorunitigegekikez.pdf
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/160a0d381b4639---44404179168.pdf
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ed235e30e5---36496993337.pdf
    • http://brunsfamilyreunion.org/clients/e/e7/e70b0594429ddd28dfd4dd2f61c76e80/File/91953729880.pdf
    • https://strechybenesov.cz/content/46821706029.pdf
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/75ij5lsmo5s8gqiucfvrbc1nmi/51345425234.pdf
    • http://adabaskimerkezi.com/upload/file/gawikefozufuniku.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=how+many+times+to+cite+the+same+source+in+a+paragraph
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001142a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1142A 16792 bytes
font_01_sfnt_off00012c41.bin
39dd9f9c25bffdcea96e376dc0566f1677bcc14b5eb7470f199c1becfa39f123
pdf-font-stream PDF embedded font (sfnt) at offset 0x12C41 11064 bytes
font_02_sfnt_off000145e5.bin
b186497380653dcdb1ad0664c911430fffff3f79d6bbdd6d3411f28f4fde8deb
pdf-font-stream PDF embedded font (sfnt) at offset 0x145E5 17696 bytes