Malicious PDF — malware analysis report

Static analysis result for SHA-256 21d131a48c992f95…

MALICIOUS

PDF

93.3 KB Created: 2021-09-05 20:22:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: 4de636634d4dd4e12ca8788800d43c3b SHA-1: 704f4511ead89ac47f6575fa13328c4132340e46 SHA-256: 21d131a48c992f954218c59396060dcf8e3206be6498338ddad4e1f3085a14e4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/24a88e078c00a809d8a35fb83e8e5fed/10616587943.pdf In PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6f32eb48c7---xozage.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ab764dd0f1c---fuxug.pdfIn PDF document text
    • https://andymullinscommercial.com/home/andy/public_html/ckfinder/userfiles/files/zijepe.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/160a5b75e05330---wixiradojegoro.pdfIn PDF document text
    • http://2440027.ru/upload/file/77764342156.pdfIn PDF document text
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a0082319796---55292418786.pdfIn PDF document text
    • http://ogcdc.org/uploads/ck_upload/files/gurexeluxekebig.pdfIn PDF document text
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/696a77fc158c71d789b1715408f2d591/zugaritakexikudutemogo.pdfIn PDF document text
    • http://klimagra.pl/images/wysiwyg_img/file/gegadajixija.pdfIn PDF document text
    • https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/n0qmefg9u49psleo6ovspqlncj/97905396646.pdfIn PDF document text
    • https://thuanxuongmonmb.com/admin/webroot/upload/image/files/vevobezopabugebozoxefa.pdfIn PDF document text
    • https://aspaeng.com/files/image/files/mexurifekuvusumapob.pdfIn PDF document text
    • http://malbreil.com/userfiles/file/nibesuxovu.pdfIn PDF document text
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16096f95966578---tabovuf.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/16134f02c953a4---vixibitelobema.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160781b5e1b4d4---62770082081.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/72i0co7t0431de5id1kqosf7p4/27178506905.pdfIn PDF document text
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/4669930cb7bfab7f7ce1db3d62da765b/zulif.pdfIn PDF document text
    • https://sieuthimaytinhcu.vn/upload/files/90033265752.pdfIn PDF document text
    • http://chapmanhighschoolclassof1968.com/clients/c/cb/cb1fed5110c07f199f416a264ee6943c/File/31583798491.pdfIn PDF document text
    • https://hotelmitrutarija.com/uploaded/files/jikawuxumezaf.pdfIn PDF document text
    • https://indacphuc.com/wp-content/plugins/super-forms/uploads/php/files/5iibjhqdaoc9k8ke1pq4a5gd14/93992335798.pdfIn PDF document text
    • https://c4ir.ae/wp-content/plugins/super-forms/uploads/php/files/o8mbgjpq298bqloj98dv58qpk3/gosadofimajovefawaledaxeg.pdfIn PDF document text
    • http://netflor.pl/upload/File/luwipevafewex.pdfIn PDF document text
    • http://k-sta.kr/FileData/ckfinder/files/20210906_B8567AF14813CF58.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=asterisknow+tutorial+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_off000106ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106FF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011f16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F16 10752 bytes
SHA-256: e5291c69586f6833d848c0849a5a44ccab2ae6779568d516f19028876e743868
font_02_sfnt_off00013805.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13805 18128 bytes
SHA-256: 7a234c2bd7ffcf73e96d08784b2f0a0b3dcb7462a84457426cf3b027b0961964