Malicious PDF — malware analysis report

Static analysis result for SHA-256 72a43e2690340d17…

MALICIOUS

PDF

73.1 KB Created: 2021-09-18 02:05:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3fa50578cc46a9160c1d5599d7ebe1ed SHA-1: 36a4d72ff0655193800731a19a487a39a4caaef2 SHA-256: 72a43e2690340d17b0961f9cb559971a7571e0a99f33e5dfa30abe92d30e9330
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many pointing to PDF files hosted on various domains. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests the document's purpose is to create a link farm, likely for SEO manipulation or to distribute further malicious content. The ML classifier and ClamAV detection confirm the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://ntpuvoice.com/ckfinder/userfiles/files/sewuvepomanorujap.pdf In PDF document text
    • https://coluer.ir/documents/file/gaziwifufumupewirug.pdfIn PDF document text
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/e535350ee8404abdef27b4f46011d95f/dowujutanumotofen.pdfIn PDF document text
    • https://www.eos.org.eg/ckfinder/userfiles/files/82776275662.pdfIn PDF document text
    • http://thietbibepnhahang.net/media/files/20460421972.pdfIn PDF document text
    • http://easy-sleep24.de/shop/images/editorfiles/file/bevot.pdfIn PDF document text
    • http://smartvoicecom.com/userfiles/zofawunapulemax.pdfIn PDF document text
    • https://jungleflightchiangmai.com/Uploads/files/dibobodumuriguzi.pdfIn PDF document text
    • http://innospectrum.eu/hirlevel/file/memesizo.pdfIn PDF document text
    • https://dtd.com.pk/ckfinder/userfiles/files/xisafixabawagorawixo.pdfIn PDF document text
    • http://pitin-akutsu.com/js/upload/files/fenogapav.pdfIn PDF document text
    • https://tuoitre.bacgiang.gov.vn/lib/ckfinder/files/pezazutegebarude.pdfIn PDF document text
    • http://rld-carbon.com/file/60909259223.pdfIn PDF document text
    • http://ekonopuntos.com/campannas/file/wipiwumipawejuxe.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/16134c9c261422---wirejolenazol.pdfIn PDF document text
    • https://ddmmaze.altruistictech.org/documents/img/upload/files/tagokexutujize.pdfIn PDF document text
    • http://toyotacri.com/userfiles/files/59391013213.pdfIn PDF document text
    • http://villa-carlshorst.de/sites/default/files/file/lovugufeveba.pdfIn PDF document text
    • http://huthamcauquanggiap.com/upload/files/97117916427.pdfIn PDF document text
    • http://uniroll.pl/user_images/file/65716271087.pdfIn PDF document text
    • https://liantoong.com/archive/upload/files/nadokazewatoz.pdfIn PDF document text
    • http://cn-daomeng.com/upload/userfiles/files/914410450a56de3a238ac389f82fcd94.pdfIn PDF document text
    • http://sutinlawkrabi.com/ckfinder/userfiles/files/7857266611.pdfIn PDF document text
    • http://landonintergroup.com/ckfinder/userfiles/files/bijabawasasamajikaz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=how+to+save+things+as+a+pdfPDF 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_off0000bcd4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCD4 10772 bytes
SHA-256: b8b7f3418ff0b874e17a6639e4ac07ad9e88b321c9c00dd8511dc0020a5ae079
font_01_sfnt_off0000d568.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD568 16032 bytes
SHA-256: b5b6cdeeca7cf9f7411d3ed7f14943523af7e0f1f19498c5068bd98bf61a2512
font_02_sfnt_off0000fe79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE79 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1