Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b57ac8dc2fbc23d…

MALICIOUS

PDF

85.3 KB Created: 2021-09-02 17:47:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 257cbd3efac7d4dd6649259fb75ba902 SHA-1: 8ca6d924f96a7475a5125613e36a4bcf70d51bb1 SHA-256: 8b57ac8dc2fbc23d7500cf555cf0543f2d59511efa608554c2fa1477ec8cda50
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with several heuristics indicating it functions as a link farm. Some links point to compromised WordPress upload directories, suggesting a potential distribution point for malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://jeneifogaszat.hu/cikkdata/files/bixivegipagawe.pdf In PDF document text
    • https://insights3.com/wp-content/plugins/super-forms/uploads/php/files/faa4bf24d7d1a0346de7212383424b30/51412339973.pdfIn PDF document text
    • http://mestav.sk/uploaded_images/file/xujejudulufusu.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e13ca6e522---rixemorovefubodolez.pdfIn PDF document text
    • https://sicurezzaips.it/uploads/file/46126251837.pdfIn PDF document text
    • https://nutstudio.it/userfiles/file/xilixufaz.pdfIn PDF document text
    • http://planao.com/ckfinder/userfiles/files/nulogolusamelotadelita.pdfIn PDF document text
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/1608ce49854903---gidefajivapovipef.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/216c227d33ec997c02844aed60bcafef/11445686750.pdfIn PDF document text
    • http://herculesestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/43853347801.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfca4f02c15---lamamuzo.pdfIn PDF document text
    • http://18554080.com/userfiles/file/14086545835.pdfIn PDF document text
    • http://outspokenholland.com/userfiles/fckFile/20210525014240.pdfIn PDF document text
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/468a3ea2d0a81615ffee7e68fbe479b4/6923764419.pdfIn PDF document text
    • https://an-professional.ru/img/files/file/pefazabobutanukeb.pdfIn PDF document text
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/d4995755b586fdc247cbaffccc78ae42/guwolikuv.pdfIn PDF document text
    • https://rhagro.com.mx/wp-content/plugins/super-forms/uploads/php/files/2dd90a2c5f159753b6781bbc2dc9b3b8/sejutakujutevijon.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/fexiko.pdfIn PDF document text
    • http://piotrkowska77.pl/zdjeciafile/monejuzewoviven.pdfIn PDF document text
    • http://ural-resyrs.ru/data/file/wogukevizumexovepe.pdfIn PDF document text
    • http://nkmate.com/FileData/ckfinder/files/20210803_1B205458A1DA8444.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/ec08b70360a41deef85bb1dd6006cf2f/jivobukidunivutaf.pdfIn PDF document text
    • https://tiguan-wiki.ru/file/sufuzifivagexunutubu.pdfIn PDF document text
    • http://eachfun.com/ckfinder/userfiles/site_eachfun_com/files/86891581098.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=the+gettysburg+address+by+abraham+lincoln+pdfPDF 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_off0000e80f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE80F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010021.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10021 17192 bytes
SHA-256: 56eda580a6f976852fc616f184931100fa0e18c578a502ed2d7a847c835305f2
font_02_sfnt_off00012cc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CC3 11384 bytes
SHA-256: f2c1456d7a0cf71c0302f629f2eafc698824c2eef44b65dda6184c640b8356fe