Malicious PDF — malware analysis report

Static analysis result for SHA-256 d55862c57f21d0ce…

MALICIOUS

PDF

74.4 KB Created: 2021-09-08 12:27:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 51b2e21fed44d49c6801e4427268e0f1 SHA-1: 8b8f30fafd8d731abc43fc7916f24029051fc962 SHA-256: d55862c57f21d0ce64608bcff875a551766254f68fa96a70eef21ef8b049a742
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm on disposable hosting, with numerous embedded URLs pointing to external PDF files. The presence of external URIs and the link farm behavior suggest the PDF is used to redirect users to potentially malicious websites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 http://corporatiegids.nl/uploads/files/gesanomin.pdf In PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/c1ia9nhh6jlru5kfbtvkd9eit5/xotejogotujomuzado.pdfIn PDF document text
    • http://interno-kazan.ru/upload/files/vuxojudusivukelilawizob.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612f09671d99f---xinivoruwof.pdfIn PDF document text
    • https://eghamatyab.com/basefile/bainbookcom/files/55775543709.pdfIn PDF document text
    • https://a-pointpro.com/cms/ckfinder/userfiles/files/49300764113.pdfIn PDF document text
    • http://wxbeimei.cn/upload/ckimg/files/202109042016429208.pdfIn PDF document text
    • https://villadelauca.com/userfiles/file/63314421034.pdfIn PDF document text
    • http://lamelove-zakryti.cz/userfiles/file/pirukibosu.pdfIn PDF document text
    • https://chameleoncoupons.com/adgprocessing/uploads/files/43165102193.pdfIn PDF document text
    • http://nebovsem.ru/app/webroot/files/files/batapi.pdfIn PDF document text
    • http://drironcat.com/images/file/naronisujudovo.pdfIn PDF document text
    • http://giorgimpianti.com/userfiles/file/29917130810.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-9-4/20210904235847406320.pdfIn PDF document text
    • http://lnv-cnc.com/userfiles/file/72808838039.pdfIn PDF document text
    • http://hyunbulsa.org/~ewedd2/userfiles/file/47469070018.pdfIn PDF document text
    • https://mtmhomeschool4art.com/mycms/uploadedimages/editorUploadedImages/file/75999524103.pdfIn PDF document text
    • http://camdohungdung.com/upload/files/32163094188.pdfIn PDF document text
    • http://amunt.madteam.net/ckfinder/userfiles/files/43276426345.pdfIn PDF document text
    • http://chayka-svg.ru/files/11063543318.pdfIn PDF document text
    • http://autoscuolapezzano.it/userfiles/files/pazegofoleritat.pdfIn PDF document text
    • https://marwaautorepair.com/nbloom/fckuploads/file/62887793801.pdfIn PDF document text
    • https://7mark3t2-7aya.com/contents/files/tuzafolab.pdfIn PDF document text
    • https://lecormier-menuiserie.com/www/upload/files/retupotezazubamonufa.pdfIn PDF document text
    • https://cuatudongbinhduong.net/uploads/files/98820451643.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=pdf+unlocker+free+download+onlinePDF 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_off0000bf27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF27 17704 bytes
SHA-256: 3321623e8f13d7a099570260651eff8d2d670e564d3d8d2e617f9a9b66fbd1c5
font_01_sfnt_off0000ec08.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC08 10484 bytes
SHA-256: 81c8a14276ed077f97a058798d49079dab24c3de16d9f85193221f673ff762cc
font_02_sfnt_off00010407.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10407 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1