Malicious PDF — malware analysis report

Static analysis result for SHA-256 a811ebc8dffd0c54…

MALICIOUS

PDF

83.4 KB Created: 2021-09-21 03:37:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d92d76f3082da8fc196948acd51e873d SHA-1: 9b78029cf40488233d16b8cf6d39fd9e59bb0282 SHA-256: a811ebc8dffd0c547b004ecc735fbd9f118e96c3a5bfde9fa8f8c0ec73a7b273
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS uploads or disposable hosting, suggesting it's designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. The presence of multiple external URIs and link farms points towards an attempt to distribute or host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://coretry.ru/uplcv?utm_term=transformers+revenge+of+the+fallen+watch+free+online PDF link annotation
    • http://xn--b1adrijbbb.xn--p1ai/upload_picture/wobimiwizezafewufomaz.pdfIn PDF document text
    • http://mywayrtk.org/userfiles/file/kowanakowiz.pdfIn PDF document text
    • http://fsoa.cn/userfiles/file/98839856124.pdfIn PDF document text
    • http://radio-salsa.fr/php/rs/filesupload/file/93875568054.pdfIn PDF document text
    • https://0a3exp.com/upfiles/editor/files/87784827010.pdfIn PDF document text
    • http://warwick-ems.org/userfiles/file/50763101619.pdfIn PDF document text
    • http://mlead.net/images/e/file/28695634055.pdfIn PDF document text
    • https://faresaldabbous.com/uploads/file/puganumibonamanoko.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161480a20d4cfb---74195939656.pdfIn PDF document text
    • http://fisioterapiasuzzara.it/userfiles/files/titarowi.pdfIn PDF document text
    • http://vivaldiskibus.com/FileData/ckfinder/files/20210919_B0057DB6FE94E3F1.pdfIn PDF document text
    • http://dinskayarealty.ru/media/file/japor.pdfIn PDF document text
    • http://korea-labels.com/ckfinder/userfiles/files/57574642990.pdfIn PDF document text
    • http://irinka.org/ckfinder/userfiles/files/11277784044.pdfIn PDF document text
    • https://blgjad.com/upload/files/pazejiposomo.pdfIn PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132ca9d3f218---66645398029.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/oe36he15d14v1gjditdnics2nc/94917293666.pdfIn PDF document text
    • https://ibshospitals.com/userfiles/file/98846972667.pdfIn PDF document text
    • http://chafewyuok.handysociality.com/upload/files/27640860266.pdfIn PDF document text
    • http://alnoorcity.com/userfiles/file/vitesemona.pdfIn PDF document text
    • http://gemwishrs.com/ckfinder/stones/files/4675057825.pdfIn PDF document text
    • https://perkunasstudio.com/uploads/files/202109051257181113.pdfIn PDF document text
    • http://life-worldwide.org/assets/uploads/files/13272204230.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_off0000e047.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE047 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f859.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF859 17840 bytes
SHA-256: 3cfb4201e07c13e618e0bfae471c80d752542696a7fc271c82cb91c41afc146d
font_02_sfnt_off00012673.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12673 10896 bytes
SHA-256: c09a564808869beb3722607184c848eeddbfa40ffb1d9b4c49d00ab8f4f6ac2d