Malicious PDF — malware analysis report

Static analysis result for SHA-256 edceb8a4d260bba4…

MALICIOUS

PDF

84.2 KB Created: 2021-09-16 16:03:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 22dbe2caf30a2ca6017fdd61eafda91f SHA-1: 2002bffa49f47adbd90f82a5e2f610e7c60b28f7 SHA-256: edceb8a4d260bba49a2fb3501cd1cc7c539b682685e1af57440cd5f49befddd6
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that point to various domains, many of which are identified as link farms on disposable or compromised hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using small PDFs as link farms on disposable hosting, suggesting an attempt to manipulate search engine results or redirect users to malicious content. The presence of multiple links to compromised WordPress upload storage further supports this. The document body is heavily obfuscated and appears to be metadata from the wkhtmltopdf tool, providing no direct user-facing content to analyze.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://cructi.ru/uplcv?utm_term=active+directory+l3+interview+questions PDF link annotation
    • http://rileyillustration.com/images/agency/files/6599822979.pdfIn PDF document text
    • https://vleek.com/uploads/files/14964288735.pdfIn PDF document text
    • https://bosingels.nl/ckfinder/userfiles/files/60134435751.pdfIn PDF document text
    • https://hagakure.by/upload/editor/files/56111664702.pdfIn PDF document text
    • http://nsk-nalogov.net/upload/files/82980197781.pdfIn PDF document text
    • http://advocaatindex.nl/images/uploads/murigadolesezav.pdfIn PDF document text
    • http://abwingsjanaf.com/uploads/files/jexaragowosoxewetuvova.pdfIn PDF document text
    • http://1night2day.com/ckupload/files/dogikirevitajelanomaxowe.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613a93a615668---1624798218.pdfIn PDF document text
    • https://borgopitti.it/userfiles/file/lorilimudikutafovaxoxani.pdfIn PDF document text
    • https://thebillionbottom.com/business_school/uploads/file/5758401807.pdfIn PDF document text
    • https://maintogelonline2.bet/contents/files/xazomogal.pdfIn PDF document text
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fdabc05e68---64011715886.pdfIn PDF document text
    • https://saatyapi.com/upload/ckfinder/files/81665318416.pdfIn PDF document text
    • http://greenflameenergy.com/userfiles/file/xitudutemepeti.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613630602bde2---69889224397.pdfIn PDF document text
    • http://duocthientam.com/uploads/ckfinder/files/37842606815.pdfIn PDF document text
    • http://business-baltic.com/myfiles/dok/vufenetapenuxidu.pdfIn PDF document text
    • http://meble-tk.pl/userfiles/file/7598555590.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613c9b4613038---89866143079.pdfIn PDF document text
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16140baafdb652---zebaxizidakinurefarimevil.pdfIn PDF document text
    • http://leebyenghun.com/new/upload/board/files/wobav.pdfIn PDF document text
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/b59fff358010dbd4769569be9bc15d47/56378207653.pdfIn PDF document text
    • 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_off0000e2b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2B5 18168 bytes
SHA-256: 4524c3dac0dab240b8e6ac2f9ab58997889453defa5ab48dbf031d2aaaa25efd
font_01_sfnt_off000111fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111FC 10864 bytes
SHA-256: bc3d71f7ddc67965d57c7ae2eef2853f78f46977063d731014f6466b50520df8
font_02_sfnt_off00012b28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B28 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1