Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4c8917012d92d35…

MALICIOUS

PDF

76.0 KB Created: 2021-09-27 07:45:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: c87d2cd06d7e425d6676a2783f631b2c SHA-1: 7790e11fdfddf59d01c9f04975fcc8fad4e83987 SHA-256: b4c8917012d92d355795540a2ac7cd006b947dfdcdf16ac801712f5f4b7e15c0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by a ML classifier and ClamAV, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, utilizing compromised CMS uploads and disposable hosting to obscure its true destination. The embedded URLs, despite some being marked benign, contribute to the overall deceptive nature of the document, aiming to lure users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/c364c37526a1c13fc1ab806cb1171b9b/sutubugul.pdf In PDF document text
    • http://sskj.pl/userfiles/file/motuzazupimejagepobefa.pdfIn PDF document text
    • http://danangsculpture.com/uploads/image/files/sebigawupekivedarelu.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1614a25a500abf---sulixizux.pdfIn PDF document text
    • http://ssanadia.in/userfiles/file/54824997648.pdfIn PDF document text
    • http://icloudcleaners.com/uploads/account/autoresponderfiles/8870355185.pdfIn PDF document text
    • http://www.brickchamber.com/ckfinder/userfiles/files/93659823018.pdfIn PDF document text
    • https://chimrodistribution.ro/poze_diverse/file/luxal.pdfIn PDF document text
    • http://occahomesearch.com/userfiles/files/12806918920.pdfIn PDF document text
    • http://rowadhr.com/app/webroot/upload/files/46474209093.pdfIn PDF document text
    • http://arhive.np-sp.ru/img/file/venowazup.pdfIn PDF document text
    • http://protectakoteasia.com/ckfinder/userfiles/files/4708334661.pdfIn PDF document text
    • https://jmclimatizacionhvac.cl/images/subidas/file/58718342067.pdfIn PDF document text
    • https://perfecthospital.org/ckfinder/userfiles/files/tepekojofokobuxemedetavo.pdfIn PDF document text
    • https://8foro.exceltur.org/exceltur_nuevo/ckfinder/userfiles/files/zoxokodabofufadugin.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1612ff5da16434---81187324834.pdfIn PDF document text
    • http://globomax.eu/userfiles/file/jezezojidapuked.pdfIn PDF document text
    • http://gomientrung.vn/uploads/image/files/mibutopirofakofu.pdfIn PDF document text
    • http://epodhajska.eu/UserFiles/File/boliw.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/1613269e839cf5---lusiluvalajidowejuvot.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/6jb9a89oku76jcp7a8vt41gvds/daripepoforusirepojuz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=6lack+ex+calling+download+mp3PDF 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_off0000bd8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD8C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d59e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD59E 19356 bytes
SHA-256: d84a25d43cf7a9df0f0122086851c2fefb33de832fc9f9b374089334aa780059
font_02_sfnt_off000108e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108E8 11016 bytes
SHA-256: f6c90e108a375fe2964ed759404bc3583bd31a1a2aedf8ed6507e01b5dabe101