Malicious PDF — malware analysis report

Static analysis result for SHA-256 ee4bf637eb39a4d6…

MALICIOUS

PDF

78.1 KB Created: 2021-09-23 05:12:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f1ccf7483a748d5cd57b4a61206b1734 SHA-1: 591ce73edad29b52de7e540fb4c1caf336100c4f SHA-256: ee4bf637eb39a4d6e7f75fc795cc32f1767d38b29e923396a34118c30ea4deae
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery via these links. Although no scripts were explicitly extracted, the nature of the URLs and the PDF structure suggest it may leverage embedded JavaScript for redirection or obfuscation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://medvor.ru/uplcv?utm_term=esther+orphan+film+streaming+vf
    • http://tea-ra.com/user_data/upload/save_image/files/zulatuvatal.pdf
    • https://solucionaesp.com/ckfinder/userfiles/files/95966538812.pdf
    • https://dhrc.in/userfiles/file/xadilab.pdf
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138712462397---saleno.pdf
    • http://inimtrento.it/userfiles/files/83207869962.pdf
    • http://gerastar.com/userfiles/file/37229192050.pdf
    • https://havadisname.com/upload/ckfinder/files/zagef.pdf
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/f3462ce1b6f6402754f40fc012209ed4/widur.pdf
    • http://xn--365-pn7mwb654m2qn.com/ckupload/files/48664560225.pdf
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161423cb73994e---60583645258.pdf
    • http://szpitalstrzelin.pl/userfiles/files/saguloda.pdf
    • https://masukpt2.com/contents/files/dowasi.pdf
    • http://fqcycpa.com/jingkelun/userfiles/files/20210912203423.pdf
    • http://9262895.ru/ckfinder/userfiles/files/65713814726.pdf
    • http://kythuatviet.vn/uploads/userfiles/file/pabadozapofugupese.pdf
    • http://paulgraphics.paulsfashion.in/files/pexapapapi.pdf
    • http://telecycling.org/files/file/fojafexobisoxikeninubo.pdf
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f1657ccd42---nonivuv.pdf
    • http://bigcool.net/webroot/img/files/zajaxelezajexosi.pdf
    • http://vizit-k.net/uploads/editor/files/sepitugexajajimip.pdf
    • http://novehorizonty.sk/userfiles/file/rixolurapakixisadiwifuju.pdf
    • http://studioguidobarbieri.it/userfiles/files/kajeregukigoz.pdf
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613bd332d5119---fetarazimoxex.pdf
    • http://bdsductri.com/upload/files/67087067151.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c84e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC84E 16792 bytes
font_01_sfnt_off0000e060.bin
e890c23db32b407920d2e066063fdd798e10ad80b1732315acd9f0f29c914e18
pdf-font-stream PDF embedded font (sfnt) at offset 0xE060 18252 bytes
font_02_sfnt_off0001101b.bin
aee55ba02e932ad6891cd63cda96d732f98ea7ab11d5e561e52db02f77541217
pdf-font-stream PDF embedded font (sfnt) at offset 0x1101B 10856 bytes