Malicious PDF — malware analysis report

Static analysis result for SHA-256 d731047f00f36846…

MALICIOUS

PDF

75.1 KB Created: 2021-09-16 12:30:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 720d10e9af7470e7289957bdbe884785 SHA-1: aeb759cd83cb804b125ef698a9aee7aeaab763c9 SHA-256: d731047f00f36846c81352506ae69dc32de52dbc2ef3c108dba0f215fe0b4ee2
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. It also features a link farm with numerous URLs, several of which point to compromised WordPress sites or disposable hosting, suggesting an attempt to obscure the final destination. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://stisk.com/file/wefipifagadezik.pdf In PDF document text
    • http://tabletopad.com/images/file/juzogag.pdfIn PDF document text
    • https://www.terraton.com.my/ckfinder/userfiles/files/silenovadik.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/5qfc0hmab5hjutimc7egh39dnj/gapewaz.pdfIn PDF document text
    • http://markone-tools.com/upload/files/54584747124.pdfIn PDF document text
    • http://kystar.net/filespath/files/20210904073807.pdfIn PDF document text
    • http://perechen-jurnalov.ru/js/ckfinder/userfiles/files/musipewuxuxovekowu.pdfIn PDF document text
    • https://s-h.cc/uploads/files/202109130321324984.pdfIn PDF document text
    • http://kurumakaitori-one.com/js/upload/files/tegorosa.pdfIn PDF document text
    • http://www.heksan.com.pl/file/nurokazadedol.pdfIn PDF document text
    • http://jysfh.com/upload_fck/file/2021-9-7/20210907181003610342.pdfIn PDF document text
    • https://jbdclothiers.net/emailer/userfiles/file/nukobavusig.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613303bdbc89d---zewoxevuseda.pdfIn PDF document text
    • http://nhadatv.com/webroot/img/files/fazuruda.pdfIn PDF document text
    • https://spyboarcams.com/files/89647669118.pdfIn PDF document text
    • https://history.tlshaa.org.tw/ckfinder/userfiles/files/ruzetinadanugotinan.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/96046779685.pdfIn PDF document text
    • http://terezszilvia.com/images/uploaded/file/kovijopedekulowure.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/161305e9f7524a---metefinisizunavuvozoleji.pdfIn PDF document text
    • https://tempatpasang.com/contents/files/50000565006.pdfIn PDF document text
    • http://apcmagon.com/userfiles/negukelojizagifagig.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=nightmare+before+christmas+putlockerPDF 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_off0000b8fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8FC 19924 bytes
SHA-256: c23a81e8e85bd7a9e49849b5d42f5571bf90c149288a32be3baf81f7e14671e6
font_01_sfnt_off0000ed04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED04 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001051b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1051B 11132 bytes
SHA-256: 2f8ef256c74721fac60321928fbc2bbd98171fcd87976c2841d1d5657296efb4