Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac856cb8e318bc5b…

MALICIOUS

PDF

69.9 KB Created: 2021-09-24 14:32:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 4a1e3c7686bdf62c7d24191efbd2b121 SHA-1: 0925a4a2f3e066397584fa33145662972fca7511 SHA-256: ac856cb8e318bc5b5cbe821e7c3069a215fc0e8cfb36660521f850f6c972bdd5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links pointing to compromised websites, identified by heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or distributing further malware. The embedded URLs suggest an attempt to redirect the user to malicious content hosted on these compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161386cca62ee0---32374910512.pdf In PDF document text
    • https://yptea.com/data/fckeditor/files/41810024450.pdfIn PDF document text
    • https://floridainvestment.cz/files/file/20605538486.pdfIn PDF document text
    • https://gesema.com/UserFiles/file/10694858699.pdfIn PDF document text
    • http://centonze-vini.com/userfiles/files/gezixewowazar.pdfIn PDF document text
    • http://in-dapt.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143cb4cae41f---jakor.pdfIn PDF document text
    • https://mamalight.net/business_school/uploads/file/dorobazisanej.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/lulaxudapub.pdfIn PDF document text
    • http://windowsplusllc.com/ckfinder/userfiles/files/tatokub.pdfIn PDF document text
    • http://dichvugiayphep.biz/upload/ck/files/18290309976.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1614256e45f758---55029495295.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/148a48aa95b8f5ca73d94f691b25a96e/bubunejetukaju.pdfIn PDF document text
    • http://vetusmeter.com/images/upload/File/domaxakumos.pdfIn PDF document text
    • https://accidentmatters.com/ckfinder/userfiles/files/rosumitumuguxalewu.pdfIn PDF document text
    • http://wamaeassociates.com/images/uploads/originals/file/70960425126.pdfIn PDF document text
    • http://warwick-ems.org/userfiles/file/muxetosebipopopawexafi.pdfIn PDF document text
    • http://ventima.ru/userfiles/file/30284083522.pdfIn PDF document text
    • http://www.yeosung21.or.kr/ckfinder/userfiles/files/1631945429.pdfIn PDF document text
    • https://liantoong.com/archive/upload/files/43297446658.pdfIn PDF document text
    • http://www.frank-diagn.hu/userfiles/files/jojetabafi.pdfIn PDF document text
    • http://gerastar.com/userfiles/file/xapuzixugabununesel.pdfIn PDF document text
    • http://rilta.net/userfiles/files/notiwinitulex.pdfIn PDF document text
    • https://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/baf199845cee3bd8664bd720d36a5fba/58621551720.pdfIn PDF document text
    • http://nirmalapublicschoolerumely.com/userfiles/file/xinedavutapolonuxone.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/f52224254ddb42c23bf1d24c640b2fad/sogoremewirugixosiwib.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=free+online+sex+games+iosPDF 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_off0000b2f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2F0 14828 bytes
SHA-256: bd41d7c54493fcfdd063a8ad03929d7d9362b2b79465e190eea6eb15135fd4bd
font_01_sfnt_off0000d88b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD88B 10432 bytes
SHA-256: 03566193fa8329b2e4b7d3b61371520c2814492c6f8501fbda526725d7e86fa6
font_02_sfnt_off0000f021.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF021 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1