Malicious PDF — malware analysis report

Static analysis result for SHA-256 558a67332551a470…

MALICIOUS

PDF

111.0 KB Created: 2021-07-08 11:47:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: ed702f93d195197a6a3f73e683ce73a1 SHA-1: a5bd85307d80199f3d82dc0ed0fb191f5cf53220 SHA-256: 558a67332551a4707f461dd339f5a518906ee13c58a13a18a845d367178f9800
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress sites and disposable hosting, suggesting an attempt to distribute malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of numerous external URIs, including those on compromised CMS uploads, supports the classification as a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://www.ecvbrass.ch/user/web/file/26647016313.pdf In PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b54d2f4a7aa---lezuribewifuxanugifug.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160d2e8965de9d---voxamovegafife.pdfIn PDF document text
    • https://thewaves.net/wp-content/plugins/super-forms/uploads/php/files/615g4v1av6ujtsd3e55l3abopj/96937097363.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6a9f487be4---77303762711.pdfIn PDF document text
    • https://pametnidom.hr/pametne_kuce/userfiles/file/27018566885.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/16079210c06247---83107311876.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/4d2e6d753b32382822170f6d952a1b3d/76109894131.pdfIn PDF document text
    • https://www.webplease.it/wp-content/plugins/super-forms/uploads/php/files/cc8oi5hlj3jk36n8t3bg3cii26/pedaxibenefuditovimut.pdfIn PDF document text
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/0ced436a4bd24c1b89f8d9d449bb8f04/kigot.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1609fbaf9ddfec---45100002565.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/160c1480ba585a---3097097871.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/glk1ua37eqbh633jl1ncrqbvje/valilokus.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085dae671a3e---85550692109.pdfIn PDF document text
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/898e39d1cb05a388acb32f3aff367720/78593607049.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/160983f0887ad8---vowawawe.pdfIn PDF document text
    • http://accessprecision.com/userfiles/file/72821829749.pdfIn PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c25a77fac4---54250652855.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160b9dc41483a3---sijen.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e11561854d---xobeled.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/f79d0ae9064e1ae53f2e0debd9373f26/85175039304.pdfIn PDF document text
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/1607b9eaff06e0---66577837038.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=student%27s+solutions+manual+elementary+number+theoryPDF 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_off00014cec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14CEC 18156 bytes
SHA-256: 4c14bea0778455c09106122198fc5c7284881e9198eafd5b5eecddbce01f2826
font_01_sfnt_off00017ce8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17CE8 10976 bytes
SHA-256: 814778843bab79570365fb7daa7008f016fe2ea14d880a6fe42ff6c02bbee647
font_02_sfnt_off00019640.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19640 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1