Malicious PDF — malware analysis report

Static analysis result for SHA-256 b71a77e6c1c714a7…

MALICIOUS

PDF

87.9 KB Created: 2021-07-18 20:59:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: f0d0d908f4b5c148332871e92bfe3d04 SHA-1: baa78407ac04a506ad22ea52933fe581a9673f00 SHA-256: b71a77e6c1c714a73d5cc627294d98a7f4ec14a1329e6c7517d8a69fac2b1ae0
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS uploads. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure and URL analysis strongly suggest a phishing or malicious redirection attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 https://spbmworld.com/anaeter_capital/siteadmin/userfiles/files/lojevugode.pdf In PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/qpnqh8frv94934n473n3qhtmif/bumifitisidipejefi.pdfIn PDF document text
    • http://bualuang101.com/backoffice/upload/files/wuwigeli.pdfIn PDF document text
    • http://abpaluso.com/upload/file/69182260906.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fd5b486b12---vepiwibap.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/1606c85fb29510---30478248736.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/cb49a26c0caaa26c0c16105d4b07bd1e/12799784335.pdfIn PDF document text
    • https://triosms.com/userfiles/file/8392470326.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/0451a7cedb8a33ee48dd31b2a8f7f14d/wizapigexezifidazudamu.pdfIn PDF document text
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/160e9240822ac8---guzuxirikemevedire.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/vtfq1tosig9p4hsfdoiflvtnoe/64714910297.pdfIn PDF document text
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160adcdcc6d54f---29767732742.pdfIn PDF document text
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/bdpduddrvh7h8uauu8pm48rc7o/58524474581.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be453e15c24---debejatovagalaratenilidu.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085d72913d0f---zijijedib.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/6391b0072d1c1ebffd986c8cf6216540/bisajemepoboluvowepeber.pdfIn PDF document text
    • http://hf1968.com/clients/48820/File/luwaj.pdfIn PDF document text
    • https://tanthueviet.vn/img_data/files/lataxibidusuv.pdfIn PDF document text
    • https://deltaguvenlik.net/userfiles/file/rexaruw.pdfIn PDF document text
    • https://linhngapt.vn/upload/files/punevevufawugidurinevezu.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b362d350b8e---1766606894.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607f434bc24b0---kituranizafud.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f6d7490392---7358772019.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/cp7bp2agpa92o7vsfrjlekb1pe/wumudefejuponivi.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1608097423a484---pivolopefegadu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=boxing+day+is+a+public+holidayPDF 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_off0000f410.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF410 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010c22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C22 17156 bytes
SHA-256: fe73222181c8274208ec67b8171cf566ad1357114d6fc271632a267a731986f1
font_02_sfnt_off00013906.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13906 10972 bytes
SHA-256: 447f123bdcecab109c6284e3583435f035fa006b16d4b3cb6a2f97ab1cc71371