Malicious PDF — malware analysis report

Static analysis result for SHA-256 8634372a8694ba0d…

MALICIOUS

PDF

90.8 KB Created: 2021-09-20 06:48:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 3b28c6e05059706c86fd792026c3b7cb SHA-1: 2008c5efc3152f4d894d213a0164edf2928806cf SHA-256: 8634372a8694ba0d9ae8054bf2a56a8db9ae30cbd6ae508b91d8476812858526
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or are part of a link farm hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or directing users to malicious content. The presence of link farm heuristics suggests an attempt to obscure the ultimate destination or to leverage SEO poisoning.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://thy-environment.com/userfiles/files/daxuwosewumitufet.pdf In PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ae75311241---20658646663.pdfIn PDF document text
    • http://brainbond.ro/userfiles/file/44063981100.pdfIn PDF document text
    • http://logicparcel.net/uploadsEditorfile/jawabepo.pdfIn PDF document text
    • https://iagclaims.endataclaims.com/ModCoreFilesUploaded/file/35936454480.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137396f4c8e0.pdfIn PDF document text
    • https://kamhosting.nl/ckfinder/userfiles/files/16532015718.pdfIn PDF document text
    • http://huthamcauquanggiap.com/upload/files/jujiwowuvasu.pdfIn PDF document text
    • https://www.sibirprokat.ru/ckfinder/userfiles/files/72145264988.pdfIn PDF document text
    • http://dongphat.net/upload/files/pexijisefuverimubaxa.pdfIn PDF document text
    • http://huyminhplastic.com/upload/files/15385883723.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9358d0446---vajapomanutuxozefanow.pdfIn PDF document text
    • http://ahdjcm.com/upload/files/65956649773.pdfIn PDF document text
    • http://galettedesrois.eu/userfiles/file/1556354807.pdfIn PDF document text
    • https://avistravel.ro/userfiles/file/vimuxaxemomo.pdfIn PDF document text
    • https://doctmcooper.com/userfiles/files/lilebamirawavew.pdfIn PDF document text
    • http://immobilieninvestors.eu/userfiles/file/zefam.pdfIn PDF document text
    • https://kop-trans.pl/uploads/userfiles/files/19376016939.pdfIn PDF document text
    • https://volgogradexpo.ru/ckfinder/userfiles/files/vusojefutevan.pdfIn PDF document text
    • http://autosvilar.com/uploads/ckfinder/files/33755240922.pdfIn PDF document text
    • http://antasboru.com/guvennet/resimlerfiles/91326865771.pdfIn PDF document text
    • https://archielectronics.com/userfiles/files/27475121452.pdfIn PDF document text
    • http://joeun-it.com/userData/board/file/19133993042.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=3d+mushroom+live+wallpaper+androidPDF 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_off0000fa12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA12 10888 bytes
SHA-256: bd97bdc279018041f61e47b23ba43e6923dd74c53295049e245b7d248da180a5
font_01_sfnt_off0001130c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1130C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012b1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B1E 19736 bytes
SHA-256: 31cac18447ae27fd1cf2bbf69401fcbcb4d68fe5b2304c7df9e1a2debdfa8078