Malicious PDF — malware analysis report

Static analysis result for SHA-256 87b27d0c3799c30f…

MALICIOUS

PDF

81.9 KB Created: 2021-09-09 17:07:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 96082aaa4b7a6c06a77f335846c86fc2 SHA-1: 4e69f66373ab8544a144f1e3a83a0a2475dd1df9 SHA-256: 87b27d0c3799c30fb2ba8abaaa138d43f8ceea3bc2caf28d56288a43788b3914
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics as a link farm, with many URLs pointing to potentially compromised or disposable hosting. The ML classifier and ClamAV also identified it as malicious, specifically as a phishing or trojan variant. The presence of numerous external links, including those on compromised CMS uploads, strongly suggests an intent to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://erictex.com/ufiles/files/39476435832.pdf In PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/jnv650diekom3mpv9ef3opuvsc/1437072947.pdfIn PDF document text
    • http://teewer.mn/ckfinder/userfiles/files/21810330538.pdfIn PDF document text
    • http://xn--80aafmoni2biho.xn--p1ai/admin/ckfinder/userfiles/files/poluremijibetezuxutetemom.pdfIn PDF document text
    • http://avvocatogiuliani.it/userfiles/files/borexawum.pdfIn PDF document text
    • http://ntep2008.com/UserFiles/File/vixalexusapa.pdfIn PDF document text
    • http://eko-baby.ru/userfiles/file/58012378751.pdfIn PDF document text
    • https://ceccarmehedinti.ro/userfiles/file/7372759843.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613430826056d---19275069244.pdfIn PDF document text
    • https://xistenze.nagydavid.com/files/files/lefirusixalovudolo.pdfIn PDF document text
    • https://artistprasanna.com/userfiles/file/lojakozefadutewewojedevo.pdfIn PDF document text
    • http://debeleven.net/UserFiles/File/49251848332.pdfIn PDF document text
    • http://nyitotthaz.hu/userfiles/files/jifuzipade.pdfIn PDF document text
    • http://smingames.com/ckfinder/files/wusinavivokolalusogez.pdfIn PDF document text
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/3002f9b0428736c4682ed2f52283816d/wuxafilijidok.pdfIn PDF document text
    • https://ladida.asia/sporlegen/administrator/imagetempfile/muporezelelumilipoxe.pdfIn PDF document text
    • https://jagamimpi.net/contents/files/57160658142.pdfIn PDF document text
    • http://kokocurry.gm/userfiles/file/migakinivaworijaneti.pdfIn PDF document text
    • https://raljob.com/userfiles/file/4063502858.pdfIn PDF document text
    • https://srmhomes.com/images/bulk_images/files/67867059866.pdfIn PDF document text
    • http://www.hangmandigital.com/files/file/zanipuzitiliro.pdfIn PDF document text
    • http://thanhnienxp.com/vietkiendo/upload/file/mojodukexuvur.pdfIn PDF document text
    • https://producto.works/userfiles/file/dexavoxajune.pdfIn PDF document text
    • https://deycaterers.com/ckfinder/userfiles/files/24871331171.pdfIn PDF document text
    • http://sarkar.ie/userfiles/file/6676050973.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=cod+points+free+warzonePDF 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_off0000d687.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD687 10624 bytes
SHA-256: 253294278793bf5b3fcf98fed386922cb99e22ca785db3a3f46dd09cd027b530
font_01_sfnt_off0000ef14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF14 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010726.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10726 19504 bytes
SHA-256: 1b0f2ac6d0449995155b9497e4375fdd695315badfa43e66b8cf0b225af58bfa