Malicious PDF — malware analysis report

Static analysis result for SHA-256 61c8c7e4dfcc59ef…

MALICIOUS

PDF

77.4 KB Created: 2021-09-12 05:49:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: b51ad69226343ce462d885d4814229b9 SHA-1: a034159b5639b951a5e9a3c5bdf4e00b8841cfb4 SHA-256: 61c8c7e4dfcc59eff65bbb70b44f33f396e9788962a938c9e83daad9e52b9471
156 Risk Score

Malware Insights

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

The PDF document contains a large number of embedded URLs, many of which point to websites hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document's structure as a link farm suggests it is designed to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://at-studio.tw/app/webroot/userfiles/files/20210901_110717.pdf In PDF document text
    • http://tungalag.mn/userfiles/files/ragexanegogabugekikafoto.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613c0359760fc---juxiliwufasadamobazus.pdfIn PDF document text
    • https://www.tratedu.net/ssss2018/assets/143ad273/ckfinder/core/connector/php/upload/userfiles/files/f9d4b724fca8d0ccee3eb1a967f4e056.pdfIn PDF document text
    • http://vietsaovang.com/uploads/userfiles/file/82134903942.pdfIn PDF document text
    • http://abwlanham.com/uploads/files/90803020997.pdfIn PDF document text
    • https://www.privathospitaletkollund.com/ckfinder/userfiles/files/29553720526.pdfIn PDF document text
    • http://mikailang.net/userfiles/file/20210902221125_1290661555.pdfIn PDF document text
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d2b1ce6d16---83698360380.pdfIn PDF document text
    • https://m-astar.com/UserFiles/files/fibexevunosefokav.pdfIn PDF document text
    • http://www.workbythai.com/admin/assets/images/40440129060.pdfIn PDF document text
    • https://kiemtoandongnghi.com/public/plugins/ckfinder/userfiles/files/21265816152.pdfIn PDF document text
    • http://mudrkanuch.sk/editor_uploads/system/files/52763671222.pdfIn PDF document text
    • http://video-cycling.de/files/file/fugur.pdfIn PDF document text
    • https://duproject.com/uploadEditor/files/ranazezakonifizuguroda.pdfIn PDF document text
    • http://honyi.tw/ckfinder/userfiles/file/gofudagatabu.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/161328a61b725e---zamevebujaj.pdfIn PDF document text
    • http://vertex-decor.com/userfiles/file/nixaxekoveba.pdfIn PDF document text
    • https://cabsfromheathrow.com/userfiles/file/saxive.pdfIn PDF document text
    • https://tutorlookup.com/ckeditor/ckfinder/userfiles/files/25635076795.pdfIn PDF document text
    • https://kentacademymiango.com/userfiles/file/29333856070.pdfIn PDF document text
    • https://khachsan295doson.vn/namthuan/images/news/files/tiwawakeke.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=jameela+jamil+impractical+jokers+episodePDF 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_off0000c8b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8B8 17964 bytes
SHA-256: 4f52ed37fb067d45a0bee6e1f3cc1a526315f798e42ebb1f75ad12b752fae328
font_01_sfnt_off0000f734.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF734 10784 bytes
SHA-256: 5b03b3b0b51516e0f0400fe8872c7869d5bccd1e1198050c83199cffd40332fc
font_02_sfnt_off00011005.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11005 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1