Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9a235ad3a15ad9c…

MALICIOUS

PDF

80.5 KB Created: 2021-09-24 02:35:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 394bbd968fc6a98437f940856384aebc SHA-1: 6dcccd7c476eb7e82b28908f7639e8fcaf41cc0e SHA-256: a9a235ad3a15ad9c16823a0b5f026edb5534a9cb4ae1b7fc8fe29eaba904463a
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and multiple external URIs, with one heuristic specifically identifying it as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to malicious sites for phishing or further payload delivery. The presence of embedded JavaScript suggests an attempt to exploit browser vulnerabilities or execute malicious code.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1614ae0cf741e4---daxudolobojitikuzekarog.pdf In PDF document text
    • https://sieuthimaytinhcu.vn/upload/files/jevebigixibarijanevul.pdfIn PDF document text
    • https://zagi.hr/files/73386304046.pdfIn PDF document text
    • https://cakesandcupcakes.net/userfiles/files/46849267212.pdfIn PDF document text
    • http://czernavendeghaz.hu/admin1/file/guduki.pdfIn PDF document text
    • https://bela.geekers.tw/upload/file_folder/file/27542586519.pdfIn PDF document text
    • http://ktcz.eu/files/files/vukoj.pdfIn PDF document text
    • http://park-seversk.ru/other/js/ckfinder/userfiles/files/72677967090.pdfIn PDF document text
    • http://emanuelarombiarchitetto.eu/userfiles/files/lepugupaladobafel.pdfIn PDF document text
    • http://gojjang.com/uploads/files/20413770923.pdfIn PDF document text
    • http://iburgisidimarsala.eu/userfiles/files/29039909986.pdfIn PDF document text
    • https://baoyi-chuck.com/ckfinder/userfiles/files/41633202170.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/8dd1a5c6f19298d07a1fd1ff243b120d/lamegufegusuki.pdfIn PDF document text
    • https://casalindasbakery.com/ckfinder/userfiles/files/leraxenokegopeweza.pdfIn PDF document text
    • https://sealordhotels.com/ckfinder/userfiles/files/42509852732.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/fagixuxirotuwitetododibog.pdfIn PDF document text
    • https://landatur.com/files/galeria/files/80978685030.pdfIn PDF document text
    • http://centrons.com/uploaded/file/4512463096144a149538c7.pdfIn PDF document text
    • https://littleedupark.com/ckfinder/userfiles/files/zozagerop.pdfIn PDF document text
    • http://t-p-fortune.com/userfiles/file/61600038907.pdfIn PDF document text
    • http://att-na.com/upload/folezuxapetogadogusatusag.pdfIn PDF document text
    • https://turismo-galicia.es/ckfinder/userfiles/files/regaduge.pdfIn PDF document text
    • http://www.investinwielkopolska.pl/application/lib/ckfinder/userfiles/files/gobevume.pdfIn PDF document text
    • http://harringtonandlombardi.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/40428938173.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=how+to+screen+share+on+mobilePDF 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_off0000d5c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5C8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000edda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDDA 17548 bytes
SHA-256: 6f459904e49acdb8fc310d271d8cba324ebc82a4fae9991a05f452eb0a67a144
font_02_sfnt_off00011bbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BBE 10712 bytes
SHA-256: 8912ff5d215f3031abbdd4fb60c8bd8adb8b3c308d6a54610a6fa3526143c6e7