Malicious PDF — malware analysis report

Static analysis result for SHA-256 851e51dea8b36253…

MALICIOUS

PDF

77.9 KB Created: 2021-09-04 13:17:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: 2f5c143f4511bc1d2d4c42f996009208 SHA-1: 3b732482a506624ab9f2894b3d10e9df2289b441 SHA-256: 851e51dea8b3625322de2f9a89b9c5036a888bb8ea056df431f4cb16dcbc0dd8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

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 0.9953

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://nomylo.ru/uplcv?utm_term=ionic+and+covalent+bonding+review+worksheet+answers PDF link annotation
    • http://rakkhunnursinghome.com/user_img/files/xipifizimilafuwenesip.pdfIn PDF document text
    • https://www.hontoys.com.au/wp-content/plugins/super-forms/uploads/php/files/lfjl1c86ks41l9hq30mdm0d3og/fezafovor.pdfIn PDF document text
    • http://tries.cz/media/images/upload/file/33774594743.pdfIn PDF document text
    • http://elskup.pl/images/assets/file/90317420274.pdfIn PDF document text
    • http://pincesorvarshop.hu/editor_up/55916798957.pdfIn PDF document text
    • https://gionggiacam.com/ckfinder/userfiles/files/zuxigomizaxovadafev.pdfIn PDF document text
    • http://toanthinh.vn/webroot/img/files/xakotizup.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/de296c8dd8fff0b1c2b9ca14585f92ea/webopenofokavikafa.pdfIn PDF document text
    • http://anapro.com/ckfinder/userfiles/files/15338686204.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b964147a5e---mixewi.pdfIn PDF document text
    • https://valdisieveshopping.it/file/78429892884.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/vodamipesagajedogif.pdfIn PDF document text
    • http://daivupaint.com/img-chamthi/files/lagoturusomomode.pdfIn PDF document text
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160f6491c7cf61---nusaxota.pdfIn PDF document text
    • http://ubytovani-budejovice.cz/picture/vtextu/file/jenikesetasaren.pdfIn PDF document text
    • https://www.asahinafunnels.com/wp-content/plugins/super-forms/uploads/php/files/89ov7umvo5ho95f7p4o3dfgq6b/bapil.pdfIn PDF document text
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/1c3df337bb1c43f5138fca00ccad6dab/74312399807.pdfIn PDF document text
    • https://mytalk7.com/_UploadFile/Images/file/7614977104.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a43c761ed4d---womidetitaze.pdfIn PDF document text
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/3ac49acedde5926a80efa3f3b4dbd763/fasoxilaxapurog.pdfIn PDF document text
    • http://gmei.lt/ckfinder/userfiles/files/49525074565.pdfIn PDF document text
    • https://havanic.com/cache/fck_files/file/83315208883.pdfIn PDF document text
    • http://slmj8.com/data/userfiles/files/govok.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_off0000cb3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB3B 10984 bytes
SHA-256: 7e6ab75b0ec1860a94a299328d3dc1876698404f6be930a124002618b7d762c6
font_01_sfnt_off0000e489.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE489 17712 bytes
SHA-256: 4f68d1ca8fb471eb7e1f51d5271997ee7f37b28c9c2f876f5403b874cc70c756
font_02_sfnt_off0001122f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1122F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1