Malicious PDF — malware analysis report

Static analysis result for SHA-256 155759e1257f1a86…

MALICIOUS

PDF

114.2 KB Created: 2021-06-27 11:50:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 4a99a7841e5bdf01954dfe4a9e632059 SHA-1: f407274e97ec9e563e366c7e26facaafa07fc4ae SHA-256: 155759e1257f1a86f1fd5cfa0dad163f6683bbc2bdc804a13c674006d27886aa
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. The file contains numerous links pointing to compromised WordPress sites, suggesting it's part of a link farm designed to redirect users to malicious content. The presence of external URIs and the nature of the links indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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://laborke.ru/uplcv?utm_term=asian+grocery+chinatown PDF link annotation
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160aeb8a454df7---wasafepag.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9fca5229b7---vapatane.pdfIn PDF document text
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e85220dbf5---39501972648.pdfIn PDF document text
    • https://unicon-msk.ru/data/files/43770839636.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e552578f3b---45864128724.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a6e46d7fd0---kevarefabifutoduviliz.pdfIn PDF document text
    • https://lightsourceindiana.com/wp-content/plugins/super-forms/uploads/php/files/dc445fe580cdf6b44d3f3507278044a1/67350349652.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/388d9a77165604ab8a90fb78c3fbf524/11526875740.pdfIn PDF document text
    • https://feltshoe.com/userfiles/file/73168768805.pdfIn PDF document text
    • http://bephoangdung.vn/uploads/ckfinder/files/gedakivufunuwigawe.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1609fac81e261a---jexuj.pdfIn PDF document text
    • http://liccuza.ro/stiri_files/file/56096482551.pdfIn PDF document text
    • https://aspaeng.com/files/image/files/tigixerovapaz.pdfIn PDF document text
    • https://sitebyside.ru/wp-content/plugins/super-forms/uploads/php/files/b1e6140284e5cf38fbe5e55a976aff30/21404229084.pdfIn PDF document text
    • https://thewaves.net/wp-content/plugins/super-forms/uploads/php/files/29hi537m1g80me5eqo3n0pd9g1/petutiv.pdfIn PDF document text
    • http://mazdooradda.com/userfiles/file/97708145800.pdfIn PDF document text
    • http://www.pilonidalsinus.gen.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16081fc130386c---69443641310.pdfIn PDF document text
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/epq02tqf2imhg463a3kvhqlnb3/vagosurupasa.pdfIn PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16088c8e01cdc3---wiziwep.pdfIn PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/1235b447fa1c6d4072dd6fd0c98469ea/jasixavunanasunev.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/40059924749.pdfIn PDF document text
    • https://pk-kuepfer.ch/ckfinder/userfiles/files/90049540461.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16093a4c68900e---18755578918.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013e4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E4A 19436 bytes
SHA-256: 2db4d41c68a1913458711ed539ad64283b1163e98b4a7230fdb32367b047b94c
font_01_sfnt_off00016f0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16F0B 8636 bytes
SHA-256: c3ef770642882723ea2da4be145f1c0539433dcbffd80af27c4265eb5b4cfa5b
font_02_sfnt_off00018aa0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18AA0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off0001a2b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A2B7 10644 bytes
SHA-256: 6b088e792cc92b1aedc79af738f57da1f060e76c5f39d7f95ebe6075e8e66a10