Malicious PDF — malware analysis report

Static analysis result for SHA-256 61cbca7a8da30930…

MALICIOUS

PDF

70.0 KB Created: 2021-09-30 12:35:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 82a98ac45f1cdf10f1ebbd57b1c79c85 SHA-1: 81f1be0a5f95691f6d1910b2039bb6425eddb5aa SHA-256: 61cbca7a8da309304e045bf318284163495e48c85858f2893894a2595ed9fcfc
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous URLs, many of which are hosted on compromised or disposable domains, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware delivery. The embedded JavaScript may be used to further obfuscate the redirection or initiate a download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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.cafeinca.com/img/public/contenido/file/89553503527.pdf
    • http://combatkuntao.com/ckeditor/ckfinder/userfiles/files/36268123385.pdf
    • https://www.babetravelling.com/ckfinder/userfiles2/files/lepav.pdf
    • http://veterky.ru/ckfinder/userfiles/files/lojepalupob.pdf
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/6bpplckredssduc8k79dapjj1e/sadorafapazivonijoxuvuwug.pdf
    • http://jjburgerut.com/uploads/files/98072203715.pdf
    • http://ahchala.com/img/file/66583540546.pdf
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16132f04864ce1---gixuwak.pdf
    • http://immobiliareborghi.com/userfiles/files/filidifaxufenovitepike.pdf
    • http://anpharma.net/upload/files/kogumexiviti.pdf
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/161460adbd833e---44520547574.pdf
    • http://dynamicyunnan.com/ckfinder/userfiles/files/xobuzo.pdf
    • http://europavloeren.nl/siteimages/file/94323292052.pdf
    • https://zibarajabi.com/cache/fck_files/file/90973316797.pdf
    • http://abpjse.news-read.com/upload/files/kajarabisubiralusedomin.pdf
    • http://nhadep30giay.com/uploads/image/files/555190075.pdf
    • https://buka.ru/sadm_files/33476709812.pdf
    • http://aliceinformaticasrl.com/user/pages/lizezofefinotokakezo.pdf
    • https://www.mnogotrop.com/ckfinder/userfiles/files/wujitoxepezexowininijelan.pdf
    • https://www.opdrrustukalac.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d5637e52c1---domojedorofuwolejedof.pdf
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16148ba47b4712---4425766699.pdf
    • https://themalc.org/files/file/lijimozejajowu.pdf
    • http://stsmcc.org/www/js/ckfinder/userfiles/files/35809984397.pdf
    • https://namhunglogistic.vn/site/files/97558709363.pdf
    • http://jonme.net/ckupload/files/97572933245.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=call+voice+changer+apk+mod
    • 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_off0000b41a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB41A 16792 bytes
font_01_sfnt_off0000cc2c.bin
2c11826a3c73161c9780c033e6b3459bd4a1c7a81ce673ff22d269c52ae64f29
pdf-font-stream PDF embedded font (sfnt) at offset 0xCC2C 14796 bytes
font_02_sfnt_off0000f155.bin
0932d1adf732d9b69a9d46c0367574800b0cf8b3dcf13cf6b6acee5615bd8584
pdf-font-stream PDF embedded font (sfnt) at offset 0xF155 10884 bytes