Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7ad69e90639e3b2…

MALICIOUS

PDF

85.1 KB Created: 2021-09-12 00:15:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 21b3a57e1c7fa8734f53608b3252d2b3 SHA-1: 3a70087e08ef02b97694b49f9b7cfda55d0b8a4d SHA-256: b7ad69e90639e3b258460fef9a4a36eb843b813d681a1022587fd6605143c589
156 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous URLs, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The presence of external URIs and the overall structure indicate an attempt to exploit users by directing them to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://backupcenters.com/userfiles/file/22464280965.pdf In PDF document text
    • https://euroquimicadistribucion.com/zabaleta/data/imagenes_contenidos/file/judutumolo.pdfIn PDF document text
    • https://liho.cz/UserFiles/File/21996295061.pdfIn PDF document text
    • http://kimdaiphatsteel.com/Images_upload/files/31615379151.pdfIn PDF document text
    • https://www.karavanlakesfet.com/wp-content/plugins/super-forms/uploads/php/files/ce0ed8d4719b36dcf5f564dcddfd42f2/68413879811.pdfIn PDF document text
    • https://www.cylinder96.ru/admin/ckfinder/userfiles/files/49824579516.pdfIn PDF document text
    • http://mestav.sk/uploaded_images/file/71339867206.pdfIn PDF document text
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/rltelaed69cvrbnpjf31gto3cq/87847464718.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136e773b9a84---38160223484.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/161343a8d685b7---rofezazepasa.pdfIn PDF document text
    • https://skvacations.com/userfiles/file/voliguwifage.pdfIn PDF document text
    • https://hzautomatisering.nl/userfiles/file/67821518.pdfIn PDF document text
    • https://questyme.ca/userfiles/file/zuxotunitepefeg.pdfIn PDF document text
    • https://saunadlaciebie.pl/userfiles/file/69778506858.pdfIn PDF document text
    • https://cornwallstaffagency.com/userfiles/file/vesoroninituwawet.pdfIn PDF document text
    • http://huspanda.com/data/ckfinder/files/92564848696.pdfIn PDF document text
    • https://cornerstonelaw.eu/userfiles/file/61966900723.pdfIn PDF document text
    • https://yogaspotny.com/userfiles/file/jonazetisetusatifos.pdfIn PDF document text
    • http://baovethanglongmb.com/upload/files/bonomekunokokazomu.pdfIn PDF document text
    • http://www.coverseg.com/uploads/ckfinder/files/tugozeta.pdfIn PDF document text
    • https://spirit-legend-enterprises.com/webroot/editor-uploads/files/tamexosoxi.pdfIn PDF document text
    • http://faw-asia.com/image/upload/files/1961709278.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=best+android+metronome+appPDF 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_off0000e78b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE78B 18056 bytes
SHA-256: 4febf1598dd12be7a63ab22aef9409b7d7e62f6fe41019b79c8510398bece8f8
font_01_sfnt_off0001167a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1167A 10560 bytes
SHA-256: bc600e06352e4810b9ab1d44098c6dcc2faa70aa0db1e10f370e3dede3d9fee5
font_02_sfnt_off00012e90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E90 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1