Malicious PDF — malware analysis report

Static analysis result for SHA-256 c51e4438d1265bb8…

MALICIOUS

PDF

78.6 KB Created: 2021-09-07 17:56:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: fac58b6a5deb1128d17a1f60901466c0 SHA-1: 0655c360749adb29abfa8f98963acad62d11372d SHA-256: c51e4438d1265bb816c4b1ca57c93685db2f5c79d89f5ffa6c560fcc1156147e
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised WordPress sites hosting further PDFs, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. The primary attack pattern observed is the use of a link farm to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/qstv9avksmqdu2mt1tf6brncc4/14725214177.pdf In PDF document text
    • https://regeneracion-capilar.com/wp-content/plugins/super-forms/uploads/php/files/62e9c09c87cdaf5c6d8c3d113fd977b9/65915586552.pdfIn PDF document text
    • https://cakkue.com/contents/files/75916280091.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160e6987f5031a---rapimifukufo.pdfIn PDF document text
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/a8174f63b6b84eb4889d7de20509bcf8/ganamifimazikixo.pdfIn PDF document text
    • http://ddaengshop.com/ckupload/files/96448578702.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e8f01c4a55---dugelorofugizazosidazoder.pdfIn PDF document text
    • http://caratow.eu/userfiles/file/vetosifetupewexinefuwebal.pdfIn PDF document text
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/160ba6a44cb9f9---lawasekimiwazepakogewu.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/cknjbg1mrk1uvvo1mg28bfckt5/52305783866.pdfIn PDF document text
    • https://dimensioninteractive.com/WYSIWYGImage/file/tekezuseb.pdfIn PDF document text
    • http://casier-a-bouteilles.fr/file/8396272554.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/160ab6dab473ea---7787774116.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/furubavofifudavuzane.pdfIn PDF document text
    • https://topjobsnepal.com/ckfinder/userfiles/files/tudowarenaguxanufupod.pdfIn PDF document text
    • http://www.kmclogistics.com/wp-content/plugins/super-forms/uploads/php/files/eaf9aab8d3f14ba977ceb079790f5e7f/bupujomivufamewikas.pdfIn PDF document text
    • https://jodhpurtravels.com/nbloom/fckuploads/file/fidibiravevenulaxugekup.pdfIn PDF document text
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/mdo8fhap6l51tcv38ss3d484hp/8017089910.pdfIn PDF document text
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/dfbaa0e67283103b04f3721122fa2c5e/93944445664.pdfIn PDF document text
    • http://mygiftltd.com/userfiles/file/22787769346.pdfIn PDF document text
    • http://iscelenie.info/files/file/tovopotepekipedos.pdfIn PDF document text
    • http://smclassof57.org/clients/34860/File/supup.pdfIn PDF document text
    • http://cristalensi.com/public/File/87219351222.pdfIn PDF document text
    • http://icloudcleaners.com/uploads/account/autoresponderfiles/77096664449.pdfIn PDF document text
    • https://shopinhome.com/ci/userfiles/files/35466843027.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=the+first+noel+pentatonix+pdfPDF 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_off0000ce6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE6D 17560 bytes
SHA-256: 10fe28caca6cd229334fecf5e6c04e12a6be58ccd3f1868c98e7431467f8772e
font_01_sfnt_off0000fc3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC3A 10660 bytes
SHA-256: 7993fc52242b9592c7b6db82534e00262c1f3cece38dd6e730e6059a127b56f9
font_02_sfnt_off0001149e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1149E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1