Malicious PDF — malware analysis report

Static analysis result for SHA-256 71331b9ebed45ea9…

MALICIOUS

PDF

81.0 KB Created: 2021-09-19 21:35:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 6fa5dfd7bf84a2e844298ef22d01b5d7 SHA-1: 53764ca0ccf4370c666ef417f5d69ceef6c941d4 SHA-256: 71331b9ebed45ea93d76d73ff01a90aa80061deb80e2a11e35705c1f61410c67
156 Risk Score

Malware Insights

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

This PDF file was flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. It contains a link farm pointing to multiple compromised websites, including one hosted on admio.ru. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the presence of numerous links to potentially malicious content suggests an attempt to redirect users to phishing or malware-hosting sites. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161415da9c136e---43919681474.pdf In PDF document text
    • http://studiobardinisrl.com/userfiles/files/42373871432.pdfIn PDF document text
    • http://kapelski.pl/userfiles/file/xefebijovutedegizi.pdfIn PDF document text
    • https://tranduongauto.com/app/webroot/files/images/pages/files/17981765890.pdfIn PDF document text
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/f1d2610bf9f84675be8c3e5b52d99e9d/50307821762.pdfIn PDF document text
    • http://safetruck.gr/images/file/mexazabajifuvu.pdfIn PDF document text
    • http://telegid.tv/userfiles/files/devobokole.pdfIn PDF document text
    • https://viettincapital.vn/upload/files/fukipikeno.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16139dffcc316c---rinojisesisugenerojava.pdfIn PDF document text
    • http://contelex.it/userfiles/files/24734245171.pdfIn PDF document text
    • https://www.peltonfell.org.uk/ckfinder/userfiles/files/kagal.pdfIn PDF document text
    • https://vaynhanh365.net/contents/files/ronufadukenulawidelave.pdfIn PDF document text
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/c62fbf79c9c92efd553f46f6318c05e7/lejalin.pdfIn PDF document text
    • http://casaledellasignora.it/userfiles/files/25019159576.pdfIn PDF document text
    • http://xn--12cm8caae5d9a0a0a1dxk6dd.com/user_img/files/9426657105.pdfIn PDF document text
    • https://ecohort.biz/userfiles/files/96912826947.pdfIn PDF document text
    • http://ansatrans.ru/admin/ckfinder/userfiles/files/78086688977.pdfIn PDF document text
    • https://ketex.com/trcgp/ckfinder/userfiles/files/genofeliwukuxomat.pdfIn PDF document text
    • http://gadkowski.pl/repository/filemanager/file/45957899314.pdfIn PDF document text
    • http://falconartistmanagement.com/ckfinder/userfiles/files/63166494692.pdfIn PDF document text
    • https://rux-thai.com/ckfinder/userfiles/files/bupefijadez.pdfIn PDF document text
    • https://samirkumarpaul.com/ckfinder/userfiles/files/zawefexatodev.pdfIn PDF document text
    • http://worshipedia.mobi/sites/default/files/file/sobap.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=thop+tv+live+2021PDF 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_off0000dd16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD16 16480 bytes
SHA-256: 31ea5a612f73bd40adf269314c63949acba8ffc463650d35e095f133cae53432
font_01_sfnt_off00010791.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10791 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011fa8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FA8 10140 bytes
SHA-256: 4fa49b5dd3d090f477efdfba204966b0fd4f6c7a62e262bdcc5e38368ea44ba9