Malicious PDF — malware analysis report

Static analysis result for SHA-256 806a667aa5844d8e…

MALICIOUS

PDF

81.0 KB Created: 2021-08-12 14:46:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: f00adb195a8b2bc090f052c3709864d4 SHA-1: 7097e4d29e5bc584fb3fb736a603db5e52aa6d73 SHA-256: 806a667aa5844d8ee8c24c4bed40bbbfac57549ae99584fea87ea0d39af6cd24
156 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for SEO spam or phishing. The document body is heavily obfuscated and does not provide direct instructions, but the presence of numerous links to potentially malicious or compromised sites is the primary indicator of its attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/r8h6qdvufq33i0knvi1e1d4su5/36796411849.pdf In PDF document text
    • http://bakoca.hu/files/file/40231074851.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160764afe7839b---60986689538.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/sokamabisare.pdfIn PDF document text
    • http://azstorestudio.com/uploads/files/wakivutufevipebasiwogir.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/a1009f31ccb42c5883972bf03d1234b1/nuwarutujajuvez.pdfIn PDF document text
    • https://dolmalatrek.com/userfiles/file/17217296397.pdfIn PDF document text
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/luvesanaki.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608b42079ffe8---42103425718.pdfIn PDF document text
    • https://discoverapartmentsforrent.com/wp-content/plugins/super-forms/uploads/php/files/28030bed1b33784c93011106fd572c3c/76407825202.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dd66e95be7d---bagupedadoxabafisi.pdfIn PDF document text
    • http://www.publicitymailing.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160a6b1c401c76---40336062483.pdfIn PDF document text
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/qak6audnb4kolns2edgs75pbt6/xitalusejobodinidax.pdfIn PDF document text
    • http://www.marcelasemper.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c79f5c9ffce---lazivika.pdfIn PDF document text
    • https://pepsima.biz/files/file/dolusekavi.pdfIn PDF document text
    • http://kasaitogo.com/uploads/files/jixuwagaso.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/9e16e50307debc0767fc1c6d417357f8/bukamalonulutekumuwef.pdfIn PDF document text
    • https://quimicasorocolor.com.ve/ckfinder/userfiles/files/gifute.pdfIn PDF document text
    • http://mail.me.ntou.edu.tw/ckfinder/userfiles/files/20210803_033022.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/miginufuribuwi.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e5f0183369d---1305609747.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/wonotedarepozakomakajun.pdfIn PDF document text
    • http://sushistoryus.com/uploads/files/18886732947.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=how+to+put+a+blackstone+griddle+togetherPDF 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_off0000d828.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD828 16968 bytes
SHA-256: 57a5c5100a61896ca79b8eb87edb9a9553d4fd57e0965667b6c884330dd6d9c1
font_01_sfnt_off00010470.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10470 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011c87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C87 11200 bytes
SHA-256: cdda8ca2cb58afee3d050f5da0aba54d4ea4637cb752a3c3dc5a7284763b555b