Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8f88997f1b8c70c…

MALICIOUS

PDF

95.3 KB Created: 2021-06-24 22:29:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: c956c7bc43ac2191aca702e226aa2910 SHA-1: e25e3ccae579342da77fa5644b111f86cf2fce93 SHA-256: d8f88997f1b8c70c1eac18321d17fe7b1b59787c241453c4f377585ae3c977c9
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised CMS uploads, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The document body's content is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16077ce701a077---23714694959.pdf In PDF document text
    • https://lacecinella.com/writable/public/userfiles/file/94427743442.pdfIn PDF document text
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/bd0fa7713b96030b57b2fef481bd1c5d/16292253753.pdfIn PDF document text
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/8042fda120cd278fbf0a0abd1b20ac15/zuwajikasoxobafojobinaped.pdfIn PDF document text
    • http://webhenevents.com/clients/868374/File/53461431180.pdfIn PDF document text
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/2287f46d3afcef4556b4c2f6d548dc7c/27204651785.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/160ac39fcceb44---bezevawebeke.pdfIn PDF document text
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/9f770a7ca1f999f50c7705048b5f0303/tedotugofigikedufopu.pdfIn PDF document text
    • http://cappellastudio.it/userfiles/files/fabinumugitilexiza.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160827fee0d56d---gorojogejalemarizos.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607f0a1cf321d---71665284007.pdfIn PDF document text
    • https://egyptsuntours.com/userfiles/files/48164583764.pdfIn PDF document text
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160745454bfbd4---5365400736.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1607b9ed2d484d---88168837947.pdfIn PDF document text
    • https://mytutr.com/wp-content/plugins/super-forms/uploads/php/files/11d243a2db84bab68d634af41f388d75/72970590090.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=wererats+dnd+5ePDF 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://scripts.sil.org/OFLIn 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_off00012487.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12487 4924 bytes
SHA-256: 36b4cf52f9afb6836dac47a3cb42944d9bd6870544840a34e0db61598072edff
font_01_sfnt_off00013561.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13561 11280 bytes
SHA-256: 167d04c57cc73cbf0a94a9e7bae70d8fba8a4d4eb9e8ee65cd750d92f97d2ddb
font_02_sfnt_off00015b75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15B75 16060 bytes
SHA-256: 5b0d2701ab39d2f69c66d7d16c60d8db0b323aa0832947137e757b5401d27330