Malicious PDF — malware analysis report

Static analysis result for SHA-256 d358c77db657f6e5…

MALICIOUS

PDF

76.4 KB Created: 2021-07-10 12:56:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 143b6675ff2a6ae82bf44db5b4f39138 SHA-1: 2c424a6feb87f333bd7f62c84aaf7e3504841d8e SHA-256: d358c77db657f6e5eddec748fc99d1d0fc85f66aa667b8a0b0ed35b018a31fc2
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript and a large number of external links, many of which point to compromised WordPress sites. This indicates the PDF is likely used for phishing or to redirect users to malicious content. The ClamAV detection and ML classifier strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://inwebjor.ru/uplcv?utm_term=carnival+sweets+and+treats PDF link annotation
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/1609853240418e---ripamubuwixeruguj.pdfIn PDF document text
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/0d9c73690040dd1b580202e8571e3a52/dugex.pdfIn PDF document text
    • http://altaprecision.com/userfiles/file/3448564673.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160904c0bce403---bibebemozakukatirexer.pdfIn PDF document text
    • https://capitalsyndic.com/userfiles/file/xovubud.pdfIn PDF document text
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/7oc9j0dsfpinaf2t0599rhlh1s/tuvurim.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/1008a1b00d0de63c2992563a2e7f9920/mesebediv.pdfIn PDF document text
    • https://nnkcreations.com/userfiles/file/62139318414.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/gnt3u9tsg1i6ubse9r8qu4mal5/wulukofogimisajibejumifas.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/630826e17bd3a01a940ab2cff099aef3/puvudojimivogedatawe.pdfIn PDF document text
    • https://vetranhtuongmamnon.vn/wp-content/plugins/super-forms/uploads/php/files/06uujh63mofdtfs336goo0bna1/kuwilu.pdfIn PDF document text
    • https://cosplay-expo.it/ckfinder/userfiles/files/79764678046.pdfIn PDF document text
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/d31b057a6fa66f38ad06be6e1b9a2fff/89883978866.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c8b0925a5a---revoxazogupemoxo.pdfIn PDF document text
    • http://carscaso.com/js/upload/files/lekesul.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_off0000c9a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9A1 10304 bytes
SHA-256: 299688dbcb438b0e596227ba610e24d58a6e4463a26edc48c0dee48e3d4f3f38
font_01_sfnt_off0000e102.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE102 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f914.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF914 17044 bytes
SHA-256: 381766f98b5592bb07850eadf4e72f5960bfcf0f6999280c897750d7e2becc4d