Malicious PDF — malware analysis report

Static analysis result for SHA-256 23367ed8b91c47e7…

MALICIOUS

PDF

88.6 KB Created: 2021-06-28 03:25:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 4bde1cbd4cbce58ebb7cd9ef50ece544 SHA-1: a1feebffd0142a8ec629dd1422e9d0deda709e44 SHA-256: 23367ed8b91c47e72a04c1bfb477b5076afbd977fb8701a7c45a220e1c7659de
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to multiple compromised WordPress sites, suggesting an attempt to distribute further malicious content or conduct phishing. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 7

  • 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.
  • 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 http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bbb8f8ab131---potij.pdf In PDF document text
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/141e50815f2d3b079001ebf324998c3a/28735862607.pdfIn PDF document text
    • http://speed-r.com/js/upload/files/luxusafinigusuguxap.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/eaf15b3d2c1afd6aa884f4850bead7b5/15644733812.pdfIn PDF document text
    • http://cleannshieldflorida.com/wp-content/plugins/super-forms/uploads/php/files/6fe71a07f2c3b0d36de8103a235e1f09/63434898606.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/51181135a02e04206cae710f95bbd561/jizupipepoxupejelo.pdfIn PDF document text
    • https://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/fc1aaad17ef889722d5a7ea9634be82c/8686175870.pdfIn PDF document text
    • http://middlegeorgiacoinclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096dd78b16d2---72092086044.pdfIn PDF document text
    • http://easyreturn.store/userfiles/file/tidazirunutabajudufevape.pdfIn PDF document text
    • http://koryosushi.com/uploads/files/57177306581.pdfIn PDF document text
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/160a0e6fcb3f6c---sulukudenodu.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ac050d9a006---xorodopatapoxutajaz.pdfIn PDF document text
    • http://www.ellisrasbetonwerke.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a7c0a64ca70---56409390114.pdfIn PDF document text
    • https://monacollection.ua/wp-content/plugins/super-forms/uploads/php/files/7464ae62bfc8d7a0c57195d837cfc277/81735669601.pdfIn PDF document text
    • https://areicon.com/images/file/50240753675.pdfIn PDF document text
    • https://balajitutorial.com/admin/userfiles/file/51036614911.pdfIn PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/ae07413a5df3e5ad9574b1e54a8999bf/zudiwawiwodoni.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160984ba008c49---dadigaxatizuranuzal.pdfIn PDF document text
    • https://securitydm.com/slicice/file/45273490266.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/lhnnu85da74n13d1284oo03v0b/2604319178.pdfIn PDF document text
    • http://www.ellisrasbetonwerke.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160c64c45ea00f---83603436313.pdfIn PDF document text
    • https://belgradenightlife.info/wp-content/plugins/super-forms/uploads/php/files/uqs9ovl3ipp40kbfnktcg2bqbt/jijopobiwivivudexujibi.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d9dbf0fcc0---ximevuxabajepifomanasire.pdfIn PDF document text
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/lnpu2lao468rm1641pg78n2i1d/19781850820.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=what+is+the+difference+homogeneous+and+heterogeneousPDF 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_off0000f6ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010f04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F04 10972 bytes
SHA-256: 5c41f65b275503b547d21a964abf09b9bd1868fb0d3704368f87c50e73cfa3c8
font_02_sfnt_off0001281e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1281E 17096 bytes
SHA-256: 444357a4c0c37b9bec5b637aa735583e63730370d9a4f04d215ab9702fdeea83