Malicious PDF — malware analysis report

Static analysis result for SHA-256 3491b7eeb8023b34…

MALICIOUS

PDF

75.0 KB Created: 2021-06-27 12:57:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 88c83f6b0c1148c2abfcd8f1a4528d01 SHA-1: f5d92ebe93bf751019869316a65a14f165a1b2f9 SHA-256: 3491b7eeb8023b34d86ba920fd2344810ef3d219944691996b05e6074044be75
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The file contains numerous links pointing to compromised WordPress sites and disposable hosting, suggesting it is part of a link farm designed to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, indicating the document's purpose is to distribute or host malicious links. No scripts were extracted, but the overall structure points to a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://medvor.ru/uplcv?utm_term=sundiang+commercial+law+reviewer+pdf PDF link annotation
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/b50d50b38c3c51cd616a6acc7e478e94/71105898296.pdfIn PDF document text
    • https://bursakaynak.net/userfiles/file/72909579463.pdfIn PDF document text
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/36b006529520555be79d5f10f88fccb4/5823892192.pdfIn PDF document text
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16086962bc9d42---jikuwokakifinabo.pdfIn PDF document text
    • http://servis-hradec.cz/files/file/96959252956.pdfIn PDF document text
    • https://www.dolphinrfid.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c85bd18c055---53428272455.pdfIn PDF document text
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609ce46b5230a---29776812225.pdfIn PDF document text
    • http://www.ximangsongthao.com.vn/app/webroot/uploads/files/9091231562.pdfIn PDF document text
    • https://humble-brag.com/wp-content/plugins/super-forms/uploads/php/files/933q6rpmhe8s5mu2pa10mk282f/kogokudoramowegosog.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c24f8a3264c---98758185862.pdfIn PDF document text
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f328178129---64195958289.pdfIn PDF document text
    • http://zkojicin.cz/userfiles/file/gojowagediku.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/4f57497312632a25d4e4c7747c4ddd38/nizopoxavelotaleraxa.pdfIn PDF document text
    • http://mimarkamilozkartal.com/userfiles/files/totajuwolakujewonapimokun.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609413f0ba8e2---pabapuronop.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/160d273d61ff2c---31519438067.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/defonuzudusabunuteforalim.pdfIn PDF document text
    • http://maxtarget.by/ckfinder/userfiles/files/4327225848.pdfIn PDF document text
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160a41d23cea26---27313005046.pdfIn PDF document text
    • http://neuragen.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b138820235a---dulimajizoginilodetipeke.pdfIn PDF document text
    • http://activesolutionelectric.com/images/file/xagejafepode.pdfIn PDF document text
    • https://maugli24.ru/wp-content/plugins/super-forms/uploads/php/files/6f9b92057fcebaac59c06f9f1ed31542/90466995813.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/e5be3ca50cc734e33059a08118e5755a/31932012865.pdfIn PDF document text
    • https://www.vbclighting.com/wp-content/plugins/super-forms/uploads/php/files/a76451f6405514628e44277cd9444ba5/zovagiwiluvofovipa.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f6b9b37ae4---13920412011.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/1p8q69sfk864qojl38j6lj0k8o/30060495326.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_off0000c077.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC077 16960 bytes
SHA-256: 6cbf944c49f3406cb2f21c3c32994347c0b6fcd8187db92eb355c72d5957875a
font_01_sfnt_off0000ecf0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECF0 11024 bytes
SHA-256: 43612f54393d554dba448b698605284c106700fa574b976ee8f3e8f86df07791
font_02_sfnt_off0001066b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1066B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1