Malicious PDF — malware analysis report

Static analysis result for SHA-256 b23ef3c8aac0fee1…

MALICIOUS

PDF

75.5 KB Created: 2021-09-15 17:18:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 9db3dd518b208ee8c06816943a21848a SHA-1: 65d85a481fbf170e6e8914893b37e6518061da16 SHA-256: b23ef3c8aac0fee1b3db358540edcfdac282f2ac48cac7d2715b660628949e00
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, many of which point to disposable hosting and are part of a link farm, indicating a phishing or malicious redirection attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to deliver a secondary payload or lead the user to a phishing site. No scripts were extracted, but the PDF structure itself is designed to host and present these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 5

  • 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.
  • 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 https://infrive.ru/uplcv?utm_term=age+of+empires+2+android+mod+apk PDF link annotation
    • http://studiopiergentili.it/userfiles/files/41555397337.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/vq97oeu2i2u6nk829rljskprmo/26685066245.pdfIn PDF document text
    • http://niktid.ru/userfiles/file/92208783955.pdfIn PDF document text
    • http://aquamedia.cn/ckfinder/userfiles/files/25245093285.pdfIn PDF document text
    • http://expnavi.com/sites/all/sites/default/files/file/venirapexisugewapeg.pdfIn PDF document text
    • https://www.blondel-bois.fr/ckfinder/userfiles/files/kutiwabovotixamolumokedi.pdfIn PDF document text
    • http://arucax.am/user_images/file/musenenama.pdfIn PDF document text
    • http://limuzine.md/userfiles/file/83789636145.pdfIn PDF document text
    • https://www.traitagri-solutions-alternatives.fr/ckfinder/userfiles/files/sejixonozosexikef.pdfIn PDF document text
    • https://feldmann-spedition.de/pics/userfiles/file/92810049239.pdfIn PDF document text
    • http://adice-area.com/pictures/files/dujebajemawusi.pdfIn PDF document text
    • http://china-spec.ru/userfiles/file/xivebadiwifamiseruwazo.pdfIn PDF document text
    • https://tranhtreo.com/images/ckeditor/files/matojukenomalewapegi.pdfIn PDF document text
    • http://photou.cc/ckfinder/userfiles/files/wifovu.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fc13a09e07---rogevewametaf.pdfIn PDF document text
    • http://energcomb.net/cms_enercomb/sgi_userfiles/userfiles/files/16577626655.pdfIn PDF document text
    • http://malovanesklomh.cz/images/file/54369283949.pdfIn PDF document text
    • http://ed-union05.ru/files/file/negiledogojas.pdfIn PDF document text
    • http://staceyasp.com/UserFiles/file/86694343286.pdfIn PDF document text
    • http://ladna.pl/user_images/file/18917547263.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/vakaguvamuposijefuzesitun.pdfIn PDF document text
    • https://highendteen.com/userfiles/files/nebukiwujinaniranipixor.pdfIn PDF document text
    • https://actionsporting.com/userfiles/files/xiregetopotobel.pdfIn PDF document text
    • 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_off0000c222.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC222 17484 bytes
SHA-256: 32a1e6dc0a6af0e41b2191e89d4bcf9422f5b12aaa105920a061333f9275bc2f
font_01_sfnt_off0000efa4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFA4 10888 bytes
SHA-256: 6237ae57d4616537c2088d53971eb9593b9adfa2c6c55da11daa30164a96638f
font_02_sfnt_off000108ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108AE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1