Malicious PDF — malware analysis report

Static analysis result for SHA-256 51d4bbebad8a5cfb…

MALICIOUS

PDF

75.8 KB Created: 2021-09-13 10:44:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 8a51d8290eb47c9825bc50e1ff298442 SHA-1: ebcebd9c97f331714ca3b0ae4324928b94889f57 SHA-256: 51d4bbebad8a5cfb0d4a6938cfdde0c728dcd2e8637c023018927accead76c25
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with numerous URLs pointing to potentially compromised WordPress sites and disposable hosting. These links likely serve as lures to download further malware or redirect users to phishing pages.

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
  • 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://0800-707-808.com/upload/ckfinder_temp/files/20210910230039.pdf In PDF document text
    • https://www.lorenzofranzone.it/wp-content/plugins/super-forms/uploads/php/files/687c2e337f828630283dc56132d74848/40625285066.pdfIn PDF document text
    • https://altaitur.com/ckfinder/userfiles/files/89984292391.pdfIn PDF document text
    • https://giaphutelecom.com/tctt/sites/aaa/file/xafidujipilunasevawam.pdfIn PDF document text
    • http://szjwwj.com/userfiles/file///65761011963.pdfIn PDF document text
    • https://thehouseproduction.net/file/93725244317.pdfIn PDF document text
    • http://tsrmmessina.it/userfiles/files/diwudizebepujiv.pdfIn PDF document text
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/oa2p4ummkq8liganknq5e206mj/10019616604.pdfIn PDF document text
    • http://yuanda-boiler.com/d/files/venogorira.pdfIn PDF document text
    • http://montaze.org/democms/userfiles/file/31316762134.pdfIn PDF document text
    • https://xn--22ck6bdp5cach0mc23a.com/ckfinder/userfiles/files/61582323946.pdfIn PDF document text
    • http://samuiluxurytravel.com/Uploads/file/lezalivetuk.pdfIn PDF document text
    • http://adbuilder.at/ckfinder/userfiles/files/padakubemek.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161372e7ebcfb7---92051512532.pdfIn PDF document text
    • http://maidichike.com/upload/files/21615478822.pdfIn PDF document text
    • http://sbriz.ru/userfiles/file/21770422879.pdfIn PDF document text
    • https://maggies-handmade.com/UserFiles/files/xaxuwaxazipezekevezabekev.pdfIn PDF document text
    • http://liveranigioielli.it/userfiles/files/79163033659.pdfIn PDF document text
    • http://firsttimehomebuyerstudy.com/images/file/sogokixeburelenewime.pdfIn PDF document text
    • http://www.johnrealestate.in/ckeditor-ckfinder-integration/uploads/files/sejukikoguzudevoviloni.pdfIn PDF document text
    • https://bselink.com/userfiles/file/sodojubeterori.pdfIn PDF document text
    • http://apsencollege.org/test/fckeditor/file/41209569928.pdfIn PDF document text
    • http://www.szphotar.com/admin/img/files/86676457379.pdfIn PDF document text
    • https://ashleymongolia.mn/uploads/files/jasin.pdfIn PDF document text
    • https://ww150007.linebot.net/upfile/files/20210904081226.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=android+vibration+apiPDF 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_off0000c59f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC59F 10224 bytes
SHA-256: 6abd0222f17d0a85539de6fed67430b3b1deea020b0d1469aea928b0fd6318f8
font_01_sfnt_off0000dc74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC74 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f486.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF486 17292 bytes
SHA-256: d3b016c1d4df34fa9d19c43e248ac9cdb5578224e4f7079d5aa9e12dae8c34d0