Malicious PDF — malware analysis report

Static analysis result for SHA-256 1142c8ab798b5fd4…

MALICIOUS

PDF

75.0 KB Created: 2021-09-20 17:13:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 5b8e06f8a9b4490645f45ba071266e30 SHA-1: 720c16f4522674e5c84c4cf3f1510e87feae89cd SHA-256: 1142c8ab798b5fd47ab197f5faf72d29851a866fe2a7caad87960ef93fccdd27
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a machine learning classifier and ClamAV, indicating malicious content. It contains numerous embedded URLs pointing to disposable domains and link farms, suggesting a phishing or malware distribution scheme. The presence of external URIs and the classification as a link farm strongly indicate an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://inwebjor.ru/uplcv?utm_term=incoming+sms+broadcast+receiver+android+example PDF link annotation
    • http://xn--dlek-5qa.com/admin/UserFiles/file/masuk.pdfIn PDF document text
    • http://lawyergz.net/uploadfile/files/24599165262.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613587392c3a3---tepimatodotagamekodezuja.pdfIn PDF document text
    • http://harposwebdesign.nl/app/webroot/files/userfiles/files/15433258840.pdfIn PDF document text
    • http://uspeh-kursk.ru/ckfinder/userfiles/files/61988638161.pdfIn PDF document text
    • http://confidenzacsapagy.hu/upload/2904579576.pdfIn PDF document text
    • http://gyermekhaz.hu/Content/site_images/files/gozavixavilav.pdfIn PDF document text
    • http://otczenacts.com/media/files/sokedatuperamilubap.pdfIn PDF document text
    • http://oawebserver.com/piceditor/file/44490140813.pdfIn PDF document text
    • https://zakarpattya-tour.com/upload/25280391987.pdfIn PDF document text
    • http://go-trec.com/wp-content/plugins/super-forms/uploads/php/files/bpvrc4ol7hu5ct0hl2ce8im20u/8897040394.pdfIn PDF document text
    • http://thuaphatlailongthanh.com/upload/contentFile/minhchau/file/70241527068.pdfIn PDF document text
    • http://tysons-cafe.com/uploads/files/buxajusofejevisuged.pdfIn PDF document text
    • http://ysmenmidwestindia.org/uploads/userfiles/file/file/jutideboto.pdfIn PDF document text
    • http://trunglamdecor.com/uploads/userfiles/file/jakesidaribu.pdfIn PDF document text
    • https://burstallconrad.com/editor_files/file/64951778545.pdfIn PDF document text
    • http://orosweb.hu/ckfinder/userfiles/files/wobaxoposodir.pdfIn PDF document text
    • http://kelakewangshangduchang.a9188.com/upload_files/art_files/files/20210906_173122.pdfIn PDF document text
    • http://peter-crooks.com/userfiles/file/64859963591.pdfIn PDF document text
    • https://quangcaonoithatgiahung.com/admin/webroot/upload/image/files/51697758302.pdfIn PDF document text
    • https://ahirealty.in/admin/userfiles/files/rinoxidexoju.pdfIn PDF document text
    • http://scamps.biz/userfiles/file/51709059226.pdfIn PDF document text
    • https://asiastudy.in/ckfinder/userfiles/files/xemaderazinop.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_off0000c039.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC039 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d850.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD850 11116 bytes
SHA-256: 2d8efc6bfdd4a2858ca9e85601efceacc98b4eb8e33068ff0fa548df50aa468e
font_02_sfnt_off0000f1dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1DC 16832 bytes
SHA-256: 150f55ffe505e95d6ae3a23b4e5fa57046c32e03a876431bfee8b8493b710cd6