Malicious PDF — malware analysis report

Static analysis result for SHA-256 39acd3f1699730df…

MALICIOUS

PDF

83.1 KB Created: 2021-09-01 04:33:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 11fdcaf1f426b8b90368fc217afdd52b SHA-1: a1d7f8ceaba02226453eaec27b02e7ab3ed70607 SHA-256: 39acd3f1699730df80532d5c14a0c9f27e06378c2777fb603aca330aa63579fc
156 Risk Score

Malware Insights

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

The PDF file 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 multiple compromised WordPress upload locations and other disposable domains. The presence of numerous external URIs suggests an attempt to redirect users to malicious content or phishing pages.

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 https://crysiq.ru/uplcv?utm_term=onenote+voice+to+text
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/16085126a4efc3---xanulemezovavadebabudor.pdf
    • https://magazinul-de-instalatii-sanitare.ro/app/webroot/files/userfiles/files/rilosodaloxativeserupezi.pdf
    • http://inkjetartandimage.com/Uploads/file/godizomafunolibabor.pdf
    • http://big-blue-bus.com/pics/fotos/1/file/90507462695.pdf
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fa6e09f349---pirebobaxa.pdf
    • http://ya-ke.cn/admin/upload/93769755851.pdf
    • http://allycatering.com/userfiles/53562748910.pdf
    • http://xn--knstlerische-biografie-arbeit-lbd.ch/userfiles/files/lugibesixidow.pdf
    • http://eastmoorclassof1970.com/clients/4/43/4343e427eb1b0a0668350338a4d6b623/File/minirudizaki.pdf
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed2e23b792---namegonipumanatixed.pdf
    • https://pataniforum.com/admin/jquery/ckfinder/userfiles/files/regekapotekutimobir.pdf
    • http://www.jamesbgriffinlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5fe2cc6bcd---3944074635.pdf
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160809ac1aaac6---13701950553.pdf
    • http://www.flamanville-76.fr/upload/file/92551584730.pdf
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/40ba73bdc3b0b02b8c8a9436b1d0e66a/fibinosidafojovula.pdf
    • https://samavetpharm.com/userfiles/files/93413533183.pdf
    • http://belgium-ex.com/images/blog//file/rilisoxozonopaxuruba.pdf
    • http://atek-ent.com/upload/file/femuk.pdf
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160abd4d1b720b---55761377007.pdf
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/160cab6f54eddc---kafilikikadagulodaroz.pdf
    • http://bjhtdszdh.com/v15/Upload/file/2021631737523839.pdf
    • https://rais.bg/uploads/file/lemufadekamogi.pdf
    • https://luxurytravel-show.com/wp-content/plugins/super-forms/uploads/php/files/d17f81bbeab4fc32e793a1db83c95f12/bareguzupogavaxakal.pdf
    • https://amd-export.com/site/upload/file/37464251244.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ddea.bin
1c7c2acfceee2968b06a7a3c8793673a0f608b66d394d968dfbbbe21a33ee4da
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDEA 9940 bytes
font_01_sfnt_off0000f40f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF40F 16792 bytes
font_02_sfnt_off00010c21.bin
7d762b136052a0214f61c9389b67be18249666166caf2bbfe0de586f56e43063
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C21 19664 bytes