Malicious PDF — malware analysis report

Static analysis result for SHA-256 870d8c56980eec5a…

MALICIOUS

PDF

81.4 KB Created: 2021-09-08 01:25:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a559c00cc7e8468a695d78529020d8f6 SHA-1: 3fa908a16b1e18fab00fa3803587f9d42f779efc SHA-256: 870d8c56980eec5a26e8c3c0c7223f8b1e103c05e55cf753e7d7258799c9d449
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to numerous external URLs, some hosted on compromised CMS uploads. The document body is heavily obfuscated, preventing analysis of its specific content, but the overall structure and URL patterns suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://lnianemarzenie.pl/userfiles/file/gonitinojakugifiz.pdf In PDF document text
    • http://dagmar-e.de/userfiles/file/liledobibosapo.pdfIn PDF document text
    • http://seventyfirstclassof69.com/clients/60772/File/5943971522.pdfIn PDF document text
    • http://tokyosushilohaus.com/uploads/files/7547261470.pdfIn PDF document text
    • https://ekransamara.ru/files/soposexodujatutaxezalep.pdfIn PDF document text
    • http://noithatachau.vn/webroot/img/files/35667429384.pdfIn PDF document text
    • https://comillaspostgrado.es/userfiles/file/wakewex.pdfIn PDF document text
    • http://www.ecvbrass.ch/user/web/file/72183629610.pdfIn PDF document text
    • https://yaslibakicisi.net/userfiles/file/34178678691.pdfIn PDF document text
    • http://www.kotolantopeni.cz/files/90342661831.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/276dee3644a848e30cd29c9c6552aa36/12417731210.pdfIn PDF document text
    • http://letnipohar.cz/upload/file/jegijuzakokunofovir.pdfIn PDF document text
    • https://www.properties-thassos.com/wp-content/plugins/super-forms/uploads/php/files/qlrda093kg8o1nnbjqbmv0agn7/43442457184.pdfIn PDF document text
    • http://bobmeetin.com/media/galleries/files/85875275499.pdfIn PDF document text
    • https://funkydrop.shop/wp-content/plugins/super-forms/uploads/php/files/92fd07b569ccc3dd21ca3f2ff390f93c/82525060370.pdfIn PDF document text
    • http://smart.sut.ac.th/tsme/src/lib/ckfinder/userfiles/files/24791127902.pdfIn PDF document text
    • https://www.kadeavenue.com/wp-content/plugins/super-forms/uploads/php/files/28b9d9eb35326fa3541369399b536fe6/guvejasu.pdfIn PDF document text
    • http://www.cddfct.com/up_files/file/genolefuxopinab.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ce586ff119a---tefuma.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/7fcb95e76bb55ff9e95c194337cd59a3/sulodena.pdfIn PDF document text
    • http://turksebruiloften.nl/userfiles/file/rufovubo.pdfIn PDF document text
    • http://hdurmuslar.com/images_upload/files/15942155938.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/37c7b9d0f0e7df8c75f5f2cee923fd97/31871346612.pdfIn PDF document text
    • https://www.straightmyteeth.com/wp-content/plugins/super-forms/uploads/php/files/d0caa81ab9e3d177e37bb495928e10ff/silesux.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=athlean+x+workout+plan+free+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_off0000d76c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD76C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF83 10696 bytes
SHA-256: 4665ae3b9f10bef05d4d71a84afc5c428a149e3d8c8d4b5edc7e462caf352e7c
font_02_sfnt_off00010817.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10817 18324 bytes
SHA-256: d75e7ed468584468dc62e452f84d1ecbee98a91d520bbb212110360b6a73bc83