Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f66b326062c45b0…

MALICIOUS

PDF

72.4 KB Created: 2021-10-08 10:28:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 1a4c346e3a3bba94d026148a4e6dbc60 SHA-1: 33aa8fafa1ba9436d3476033d02238d4d24f3b20 SHA-256: 5f66b326062c45b046efc61e37af9a8958196c87e832bf6464ea5d214aff6319
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to other PDF files hosted on various domains, some of which appear to be disposable or compromised. This pattern is commonly used to obscure the ultimate destination of malicious content or to distribute phishing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://21cedu.com/pds/userfiles/files/wedorurit.pdf In PDF document text
    • http://kcpsystem.com/userData/board/file/sovufaxoxexovat.pdfIn PDF document text
    • http://nexxosrealty.com/userfiles/files/35204393180.pdfIn PDF document text
    • http://1night2daytour.com/ckupload/files/73047383726.pdfIn PDF document text
    • http://rcsiprojectracker.com/userfiles/files/nokatebumunudogadi.pdfIn PDF document text
    • https://sledovani2.gpshlidac.cz/www/userfiles/files/66363552849.pdfIn PDF document text
    • http://susasoft.com/upload/userfiles/files/jogakoluwiwugoz.pdfIn PDF document text
    • http://efcosmetic.com/uploadfile/files/33939753310.pdfIn PDF document text
    • https://www.meditech.cz/ckfinder/userfiles/files/5710300289.pdfIn PDF document text
    • http://sooam.com/files/fckeditor/file/14732511676153850d7d549.pdfIn PDF document text
    • http://n3ss.ro/ckfinder/userfiles/files/24689394396.pdfIn PDF document text
    • https://adepotcustom.com/UploadFiles/file/20210902181354163.pdfIn PDF document text
    • http://iccjsc.com/images/uploads/files/ritavon.pdfIn PDF document text
    • http://dailyxedayhang.com/userfiles/files/busaxemusuleg.pdfIn PDF document text
    • https://n-zvuk.ru/upload/file/87678949430.pdfIn PDF document text
    • https://zooiguana.pl/app/webroot/media/files/xelonowinexabozufit.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615ce85bb53c5---9735206352.pdfIn PDF document text
    • http://alibabashipping.com/userfiles/file/9716533983.pdfIn PDF document text
    • http://edwindijk.nl/home/edijk/domains/edwindijk.nl/public_html/uploads/file/63845362002.pdfIn PDF document text
    • http://hasadtemizlik.com/upload/file/tonakozabavetexeronito.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/157d38df5c5d620a8a88f282e3726123/mefojulusuzizagafibapi.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/16152e47dd176a---30147396002.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=elimination+reaction+with+examplePDF 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_off0000ba9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA9F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d2b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2B1 16168 bytes
SHA-256: f20a7335403ee0ea93daf5faf031aee27748bf89ac3e942ec31d3a0e66e95cdf
font_02_sfnt_off0000fbc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBC3 10640 bytes
SHA-256: 7d9bda356d8bb0e534e9031765e17fe10ab1ffc39fb17bbbe00139cf851d9a33