Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6772770fa24b13e…

MALICIOUS

PDF

97.7 KB Created: 2021-09-15 10:07:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 6e5ce93b6dbda6eb67547a7a578be73d SHA-1: e3e142f43865b7c6d7a595576bbe9fcf32b08064 SHA-256: b6772770fa24b13ea91876af9c387da24b0f598bc185e2a9fc9ea24e9f2bc83c
156 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm used for phishing or malware distribution. The presence of external URIs and link farms indicates an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://rebornfair.com/FileData/ckfinder/files/20210912_5975DD5B3313B541.pdf In PDF document text
    • https://callhfelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fb786ce638---dajuzebijosa.pdfIn PDF document text
    • http://citra.cl/userfiles/file/juremuxagisi.pdfIn PDF document text
    • https://sportsht.com/userfiles/file/97086494394.pdfIn PDF document text
    • http://zit-tech.com/userfiles/files/lowozitumawitoxike.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/16136be135f216---30487125098.pdfIn PDF document text
    • https://aucordechasse.fr/vosImages/5549821548.pdfIn PDF document text
    • http://thrifty-uy.com/files/others/sunowifiwakalazemokedisul.pdfIn PDF document text
    • http://leebyunghun.kr/new/upload/board/files/wefew.pdfIn PDF document text
    • http://e-photo.lv/ckfinder/userfiles/files/guzage.pdfIn PDF document text
    • https://bitree.ru/ckfinder/userfiles/files/sobuxaxamosanin.pdfIn PDF document text
    • http://xn--80aafjbawrcdgsodbdciig4a5v.xn--p1ai/pict/file/senasov.pdfIn PDF document text
    • http://nattuvaartha.com/assets/ckfinder/core/connector/php/uploads/files/65209953842.pdfIn PDF document text
    • http://greenearthgardens.org/userfiles/fuzejosuwakobafeduregan.pdfIn PDF document text
    • http://www.temaricerca.com/entry2013new/admindia/ckfinder/userfiles/files/sikigudivujopubo.pdfIn PDF document text
    • http://stefanourso.com/public/userfiles/file/26599368896.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/ba41d1e43cac8ba7b52d4a6ce594887b/32576621849.pdfIn PDF document text
    • http://autoscuolemontagna.it/userfiles/files/18306935108.pdfIn PDF document text
    • https://g4m3s-4p1-12s1.com/contents/files/golagarinesezebaveze.pdfIn PDF document text
    • http://maybomnuocdanang.com/uploads/image/files/68989729936.pdfIn PDF document text
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1614061491d2d1---bupuxolov.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613378231e433---88605296842.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=game+of+thrones+android+wallpaperPDF 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_off000114e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114E5 19308 bytes
SHA-256: e781dba36ed0b63efaf0377e9d9e6361aca61d75c689464dcf04fa446ff5ddf8
font_01_sfnt_off000147e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x147E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015ffc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15FFC 10888 bytes
SHA-256: 105def9a1b8cf049ba24cc2c019de8fc550c9a9b69aef84f2effa8130625849e