Malicious PDF — malware analysis report

Static analysis result for SHA-256 6e123b03b0565f11…

MALICIOUS

PDF

87.8 KB Created: 2021-09-12 22:13:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: aa814d3569bd9498b36ac5331160cd0e SHA-1: abec38e67092d2312b50e36942571d8b83e4500c SHA-256: 6e123b03b0565f112355f9d30c4c38ff546d71ca04ea0062d7544a4a20b09dbf
156 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs, many of which point to compromised WordPress sites used for file hosting, suggesting it's part of a phishing or malware distribution scheme. The presence of a link farm on disposable hosting further supports this. The ML_NYX_PDF_MALICIOUS and CLAMAV_DETECTION heuristics indicate a high likelihood of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://studiolegalezullo.eu/userfiles/files/repewekij.pdf In PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613d523968da8---65666128480.pdfIn PDF document text
    • http://chrislahoda.ca/userfiles/file/28737488120.pdfIn PDF document text
    • http://yearbookplus.com/uploads/ckfinder/files/norosudikaber.pdfIn PDF document text
    • http://qhzs88.com/admin/fckeditor_upfiles/file/2021091011161380554.pdfIn PDF document text
    • https://rotterdampools.com/contents/files/82237228322.pdfIn PDF document text
    • http://www.julietlandau.com/fckeditor/userfiles/file/vopuposoxibowasode.pdfIn PDF document text
    • https://www.sensiblemachines.com/ckfinder/core/connector/php/files/zorupojivuledopiged.pdfIn PDF document text
    • https://perfecthospitals.com/FCKeditor/file/bomud.pdfIn PDF document text
    • http://lamekatus.ee/uploads/ckeditor/files/daxazuxaganefiwodewisuta.pdfIn PDF document text
    • https://mailing.crpm.ch/ck/ckfinder/userfiles/files/sefogejufituz.pdfIn PDF document text
    • https://ekoelprom.pl/public/images/editor/file/94108408872.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/esjs1d3mqel8ro90qhhi62jsc2/91310813606.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e3e43de714---xibum.pdfIn PDF document text
    • http://gleb777.com/fck_upload/file/lijukigiluwemasozeref.pdfIn PDF document text
    • https://washlounge.in/ckfinder/userfiles/files/26274147381.pdfIn PDF document text
    • http://vagtteam.com/userfiles/Files/wuwexarizonugoj.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613990eb7d618---72815370295.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/161387f24373ad---vofike.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16132c589bf4f5---depozeriwubumade.pdfIn PDF document text
    • http://schodylux.pl/userfiles/file/8899184169.pdfIn PDF document text
    • https://cometgroupinternational.com/ckeditor/ckfinder/userfiles/files/90605346380.pdfIn PDF document text
    • https://samsungvrvklima.com/upload/ckfinder/files/93976033237.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=androrat+apk+binder+builderPDF 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
stream_005_off00013965.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x13965 10532 bytes
SHA-256: 5302af59bceadce752a1736e349ecaf74c45daf8c8b846a97dc1d43ecd83a023
font_00_sfnt_off0000e846.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE846 22144 bytes
SHA-256: 4ec8752c17ef20fce58bf10be2ed274a08f07b8a74f605e4930ba3aafc222b42
font_01_sfnt_off0001214e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1214E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1