Malicious PDF — malware analysis report

Static analysis result for SHA-256 875a74cae6bda7cf…

MALICIOUS

PDF

82.6 KB Created: 2021-09-08 07:44:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 98fbabc7febec2eada2b2a12c5dc9389 SHA-1: 0c4dd7e574f40938a82b5a79c323794bad9e7b5e SHA-256: 875a74cae6bda7cf0ae2500de3b7c4bea0a0e25604102ec69afd52f1a0e966ba
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to redirect users to malicious content or phishing pages. The embedded JavaScript is likely used to facilitate these redirects or obfuscate the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9168

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://smidgel.ru/uplcv?utm_term=technique+of+data+analysis+pdf PDF link annotation
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a9a53c7c3c---sufik.pdfIn PDF document text
    • http://blog.crowdly.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078b78bf3261---dokoderubir.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/86675c9ed103a73a38e08d6887490332/xosemulusejebab.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/9v67l73ku6ve9m9ofntvpgj9ko/60840071541.pdfIn PDF document text
    • http://sanchariglobal.com/userfiles/file/dudaj.pdfIn PDF document text
    • http://gaongonmaiphuong.vn/webroot/img/files/ziburirasetakerifoma.pdfIn PDF document text
    • http://steelbo.com/uploads/admins/u0/files/20210805081346.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/jebujejosijatanojokukurun.pdfIn PDF document text
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/b53d348c5eb811363cb599e7c9383a10/tejajomowafiganudebegi.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc3765e6374---59616852342.pdfIn PDF document text
    • https://aihr-iadh.org/uploads/FCK_files/file/wegiwitigimuderovep.pdfIn PDF document text
    • http://daehwa.info/uploaded/file/wajemetenutifig.pdfIn PDF document text
    • https://muratay.nl/userfiles/file/lirugajojetujukam.pdfIn PDF document text
    • http://www.jacenter.org/js/ckfinder/userfiles/files/palam.pdfIn PDF document text
    • http://appinaris.net/ckfinder/userfiles/publics/files/53748089633.pdfIn PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/7qg35gc4ct9o2r9gpaak95bin5/73747218978.pdfIn PDF document text
    • https://www.marjojaspers.nl/ckfinder/userfiles/files/nagumozuzolonam.pdfIn PDF document text
    • https://fastcomputer.vn/wp-content/plugins/super-forms/uploads/php/files/3c941c2cf3dd5a814e9f900fa4a356ca/wewarorokewixozifapuvikex.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e587e85e827---82606721681.pdfIn PDF document text
    • https://gadd-asso.org/userfiles/file/bamokimir.pdfIn PDF document text
    • https://gmnavarra.es/ckeditor/files/57424543194.pdfIn 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_off0000e67a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE67A 10940 bytes
SHA-256: 45a259b1ab0aee4120fdda9a719582b4502e3187b6c43f976fc8482208c1eaaf
font_01_sfnt_off0000ffa1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFA1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000117b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117B3 18476 bytes
SHA-256: d4d64981f4907b0a172d7be2999e354b2e6e6ff6d4df5789d8393fdc0d6f4cd8