Malicious PDF — malware analysis report

Static analysis result for SHA-256 6debd912551ac9d3…

MALICIOUS

PDF

77.3 KB Created: 2021-09-19 06:05:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4541e122f37ac46a73fc948b3095fa9e SHA-1: 18a7e2609dac5e51b673d475ebfca7db35a4e82b SHA-256: 6debd912551ac9d3b037cf8751380ef058b55cc1b86e73c785aed872b25a8bcd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to external websites, many of which are hosted on compromised CMS platforms or appear to be part of a link farm, suggesting an attempt to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly indicate a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://kemxoi.vn/app/webroot/files/images/pages/files/fobuk.pdf In PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161393e7656dd4---bovativev.pdfIn PDF document text
    • http://arnoldbolingbroke.com/ckfinder/userfiles/files/47560873703.pdfIn PDF document text
    • http://kaizenlife.com/ckfinder/userfiles/files/ganasewirilifazibo.pdfIn PDF document text
    • http://hongdanhaudio.com/luutru/files/21397783965.pdfIn PDF document text
    • https://www.abrasco.org.br/ckfinder/userfiles/files/97456987014.pdfIn PDF document text
    • http://ecohouse-lab.de/userfiles/file/37259310587.pdfIn PDF document text
    • https://motoquadro.de/userfiles/file/kojesanapaserubopajutuwa.pdfIn PDF document text
    • https://specialgarden.ro/userfiles/file/lokumalato.pdfIn PDF document text
    • http://1night2day.com/UserFiles/file/98210515503.pdfIn PDF document text
    • http://pscemetery.com/userfiles/file/kidalemuza.pdfIn PDF document text
    • http://mjacz.cz/soubory/files/59896988254.pdfIn PDF document text
    • http://dolinakrzeptowa.pl/public/upload/ckfinder/userfiles/files/18565686497.pdfIn PDF document text
    • http://autoscuolepintozzi.it/userfiles/files/watubu.pdfIn PDF document text
    • http://avesta-hmora.boj.se/uploads/userfiles/files/3678803580.pdfIn PDF document text
    • http://ke-sen.com/userfiles/file/1631737437.pdfIn PDF document text
    • http://domosplast.hu/files/file/vukemugepesejizatili.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16132c3b48ab9d---48289084974.pdfIn PDF document text
    • http://g-shocktou.com/user_file/file/pifunopulaxegawajelojizi.pdfIn PDF document text
    • https://siam-royal-view.ru/data/files/5655510282.pdfIn PDF document text
    • https://fsreloading.com/userfiles/files/fewevowupifuripudejuvujib.pdfIn PDF document text
    • https://gagiongvitgiong.com/ckfinder/userfiles/files/lexepiwukagufakizor.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161421251b2dbd---28272726615.pdfIn PDF document text
    • https://frontivo.ro/userfiles/file/wogaraninugajinijowu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=marathi+magazine+free+downloadPDF 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_off0000c286.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC286 10772 bytes
SHA-256: e899a3b3f0c6040f30d80129e408c63997f3df054955d190f446314f40216646
font_01_sfnt_off0000daff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAFF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f311.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF311 20108 bytes
SHA-256: 78a7b2d1834aebd94a394717a24446478fe6879604bcf315d4b8696982f529e3