Malicious PDF — malware analysis report

Static analysis result for SHA-256 78de26da943f0d1a…

MALICIOUS

PDF

79.8 KB Created: 2021-09-12 08:28:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 58d5fff8cbb7a0ed009af17a445820e0 SHA-1: aaee5070214a0b57bcc3c9ee97dd334f9e52b5ac SHA-256: 78de26da943f0d1a0d60a128e41d2b693e6be6d0b20923df13de3652cd5fe813
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The PDF was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV detection, indicating malicious intent. The 'Browser extension / update installation lure' heuristic strongly suggests a social engineering attack aimed at tricking the user into executing malicious code. The numerous embedded URLs, many on disposable domains, further support the phishing and malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://inwebjor.ru/uplcv?utm_term=chrome+apk+for+pc+download PDF link annotation
    • https://kudamatsu.org/userfiles/file/70105781005.pdfIn PDF document text
    • http://ahkkpcm.org/userfiles/pilularewunajinubisegow.pdfIn PDF document text
    • http://sartoriaventurini.com/userfiles/files/1714278768.pdfIn PDF document text
    • https://www.hinkler.com.au/application/third_party/ckfinder/userfiles/files/93467840367.pdfIn PDF document text
    • http://vipforiraq.com/userfiles/files/67149454346.pdfIn PDF document text
    • https://cardolf.ro/files/62657609411.pdfIn PDF document text
    • http://thephinhmienbac.com/upload/files/koladopoxutigogedumukol.pdfIn PDF document text
    • http://kstarsmall.net/userfiles/file///47446403618.pdfIn PDF document text
    • http://umhouses.com/uploads/files/14194946181.pdfIn PDF document text
    • http://komodovo.ru/upload_picture/fogugomepod.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135ba4185b3e---62958532200.pdfIn PDF document text
    • http://machulski.com/public/file/5598778115.pdfIn PDF document text
    • https://pmrmhss.com/userfiles/file/91957166061.pdfIn PDF document text
    • http://lightningriskassessment.com/ci/userfiles/files/sakajunir.pdfIn PDF document text
    • https://anninhsieuthi.online/upload/files/jipixevazekekipe.pdfIn PDF document text
    • http://movesearchesuk.com/userfiles/file/59299724858.pdfIn PDF document text
    • https://md-bud.pl/szklo/photos/file/sidupog.pdfIn PDF document text
    • https://tideandtigers.com/ckfinder/userfiles/files/10811740125.pdfIn PDF document text
    • http://woodbridgeabw.com/uploads/files/8106919875.pdfIn PDF document text
    • http://duquenne-moteurs.fr/webroot/upload/files/24279712235.pdfIn PDF document text
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161314ec5a249c---womamadasawomitedawirot.pdfIn PDF document text
    • https://citrasas.com/ckfinder/userfiles/files/25234044950.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_off0000d22c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD22C 17936 bytes
SHA-256: 64baaec1cf5c6be185105899d4eebcd07d587aaa3862b94ea7160397b4553ffb
font_01_sfnt_off000100fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011913.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11913 10736 bytes
SHA-256: 14fab76418fe14fe768bf3007b27befc4abcf526739a7ea2360b02c63563aedd