Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c137adabf101551…

MALICIOUS

PDF

70.1 KB Created: 2021-09-28 05:53:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3eb7e989bd01deb3520a56e96acb68fa SHA-1: 854ca7b146a8df89fb00deceafe96fe4d16e221b SHA-256: 1c137adabf1015513c67e02b0757d9ec4ca42518f241481309766007b9fa627a
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to disposable hosting or compromised CMS upload directories, characteristic of a link farm used to distribute malware or conduct phishing. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were extracted, the structure and URL patterns suggest the PDF is designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://www.superior-inkjet.com/login/ckfinder/userfiles/files/gewamo.pdf
    • https://hoangmailogistics.com/asset/site/files/28866609472.pdf
    • https://endeligmandag.no/e-brev/data/div/16337322671.pdf
    • http://jrecchina.com/ckeditor/ckfinder/userfiles/files/59356152939.pdf
    • https://clubforeducation.com/FCKeditor/userfiles/file/57528595433.pdf
    • https://ikra-ekb.ru/files/fckeditor/file/
    • http://cancunday.com/travela/img/files/livagibixopili.pdf
    • http://awfiowv.love-mrt.com/upload/files/xepowajizurul.pdf
    • http://firsttimehomebuyerstudy.com/images/file/sogifo.pdf
    • http://anshan56.cn/userfiles/file/16318238431327701165.pdf
    • https://fiberglasssupplydepot.com/userfiles/file/67774702026.pdf
    • https://villamishkan.com/310renonew/front/images/files/84261946673.pdf
    • http://104408017.linker.tw/files/givajusafigitawenaj.pdf
    • http://sanga.asia/userData/board/file/19471281566.pdf
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/161419988c93dd---76131301236.pdf
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/1615142707121a---sozepaxuwif.pdf
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/a87acbf5b036199293a86f1078d03d0f/80500952386.pdf
    • https://avflash.nl/upload/files/25397430241.pdf
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/161416442810a3---45646033217.pdf
    • http://sonarkella.com/userfiles/file/54178869426.pdf
    • http://kasand.com/userfiles/radajalodi.pdf
    • http://cavusofis.com/images_upload/files/59011732920.pdf
    • https://euronet.stonavka.cz/webpagebuilder/ckfinder/userfiles/files/35385126896.pdf
    • https://bdblue.com/ckfinder/userfiles/files/pulokijaxi.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=sewing+emoji+android
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000af4a.bin
521cd22b74e8179db5bbfcdfaf5a9d6ca41b816a1a1f4fe31364b6eb3355c91b
pdf-font-stream PDF embedded font (sfnt) at offset 0xAF4A 16988 bytes
font_01_sfnt_off0000db1f.bin
11c8b22e4e9c91c8749c35b37735eb831b625bab2fa59b89ce7be375d9f7e0d1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB1F 10572 bytes
font_02_sfnt_off0000f307.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF307 16792 bytes