Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9fa4e1fc2d0182e…

MALICIOUS

PDF

88.8 KB Created: 2021-08-01 13:25:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 52ee0c864c624f47250cb0416703a1fb SHA-1: c35d1bdfd1eaea5e4580ae5882c718b4e4a384b5 SHA-256: b9fa4e1fc2d0182ed9e0a25eea35d738a2e00f96cc053fc7a5c9ac4f3606c2c9
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many pointing to compromised WordPress sites. These links form a link farm, a common technique for distributing malware or directing users to phishing sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 7

  • 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.
  • 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.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/1e204bu45uvmlfue8ek4n5n246/14382025096.pdf In PDF document text
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/584e98650cf4800d43df65f201549a49/26877604707.pdfIn PDF document text
    • http://wujipacking.tw/upload/files/vagiwaferuf.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160a149df74758---21741737228.pdfIn PDF document text
    • http://aelma.com/sites/default/userfiles/file/firope.pdfIn PDF document text
    • https://1877painters.com/FCKeditor/file/powijopaxuputurapozadak.pdfIn PDF document text
    • http://commandhousecreations.com/uploads/files/febopozej.pdfIn PDF document text
    • http://hourinkan.net/js/upload/files/jojidofemesofeniro.pdfIn PDF document text
    • https://srp-galabau-rostock.de/wp-content/plugins/super-forms/uploads/php/files/mqjntredab8ht78tkbhkbgtvth/kufuvuturuxavedufegi.pdfIn PDF document text
    • http://vladjurnalist.ru/archive/file/19340212096.pdfIn PDF document text
    • http://angarakshaksecurity.com/userfiles/file/27817117889.pdfIn PDF document text
    • http://asbufestival.com/uploads/FCK_files/file/lozopozonumopigusalok.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/1ff5313e83578603ce12b317fe685a88/65602848079.pdfIn PDF document text
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bd76c50ae43---55671490171.pdfIn PDF document text
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/89rj2o78ob1kerslednpl22aa7/67020122586.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a46384ec839---88050807911.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ef1ffce5d7---3578816065.pdfIn PDF document text
    • http://oakgroveschoolheritage.com/clients/b/bc/bc5c94904a1f00f1300372e6f875146f/File/mewavotopatuwekixoneguxul.pdfIn PDF document text
    • http://fatamorgana.fr/uploads/assets/file/fululovurovolav.pdfIn PDF document text
    • https://kingyao.com/uploadfiles/files/20210613_091835_9277.pdfIn PDF document text
    • https://chiataiec.com/userfiles/Proj_Name//files/29386698852.pdfIn PDF document text
    • http://tmtechvn.com/webroot/img/files/17860462467.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=verbo+to+be+exerc%C3%ADcios+6+anoPDF 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_off0000f17f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF17F 19960 bytes
SHA-256: fabb53d22a3d9bd6fb6e14dc335170ccdfe689c8345440504b2a25f6c8302051
font_01_sfnt_off0001228b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1228B 10620 bytes
SHA-256: 2dbb54a77ba444014b9cec839bc793d51a4c50331547bddca32fc84c848fddea
font_02_sfnt_off00013b0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B0C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1