Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc1a09569fd4b8a5…

MALICIOUS

PDF

70.7 KB Created: 2021-09-27 00:31:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 11d3b0b678c7f0a62dcadbacd8a03e5b SHA-1: feb3193f445d9b5cb29fd79dd14f4257504a3980 SHA-256: dc1a09569fd4b8a581e9b7623b7aa1500f360e28c503b46ac58af9e34110b80d
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to compromised WordPress uploads and other disposable hosting sites. The embedded URLs and the overall structure suggest an attempt to distribute malware or conduct phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://gwtcs.org/Content/uploads/files/86444098510.pdf In PDF document text
    • https://muzeumkonstancina.pl/attachments/file/41415487931.pdfIn PDF document text
    • https://tahuacoop.com/cms_gpadmin2015/sgi_userfiles/userfiles/files/13790216870.pdfIn PDF document text
    • http://chiesamadremarsala.eu/userfiles/files/54492599744.pdfIn PDF document text
    • http://fratellibeninca.com/images/file/tujurij.pdfIn PDF document text
    • http://siblom.ru/files/upload/file/59461759165.pdfIn PDF document text
    • http://telekommarketing.com/firme_data/files/wubusipovala.pdfIn PDF document text
    • http://ilovechardonnayhills.com/userimages/juvonijamifovilixiza.pdfIn PDF document text
    • http://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/kuvakokodasulu.pdfIn PDF document text
    • http://thebrownbag.vn/upload/files/51016008506.pdfIn PDF document text
    • https://rajakeempat.com/contents/files/17148492100.pdfIn PDF document text
    • http://tsg-vaganovskoe.ru/ckfinder/userfiles/files/fisona.pdfIn PDF document text
    • http://sicompk.com/survey/userfiles/files/57289714679.pdfIn PDF document text
    • http://karaokejdi.com/ckfinder/core/connector/php/upload/files/70177334899.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/44cada170e742860634d2ebffe797814/85028888992.pdfIn PDF document text
    • http://artediapharma.com/upload/files/71619932395.pdfIn PDF document text
    • https://accounting789.com/ThImg/file/75423195119.pdfIn PDF document text
    • http://quiltingacademy.com/fckeditor/userfiles/file/38851117842.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613347368bbd7---97376174256.pdfIn PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/ei3rn3hcqk7t45mk8n5k0e0rqe/rejawemaverutebab.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/161409e76337b3---6761331595.pdfIn PDF document text
    • http://dxline.eu/userfiles/file/72479421481.pdfIn PDF document text
    • http://angel-conference.org/upload_fck/file/2021-9-19/20210919093702238008.pdfIn PDF document text
    • http://sudeoksa.com/userfiles/file/20210918112452.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=happy+birthday+fire+gifPDF 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_off0000b197.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB197 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c9ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9AE 10584 bytes
SHA-256: af2b70af8252289de76d3499f22365641799eb040730b01f5d641662ca9f066f
font_02_sfnt_off0000e17f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE17F 17604 bytes
SHA-256: f66f1fb5aa7d7ad450aeddf283dcb51f87c3b4fc03f0cfaffe56496969fa7c40