Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4443e6458497f82…

MALICIOUS

PDF

81.6 KB Created: 2021-09-16 11:56:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 4e5c98ca653a3391794acbff807f5602 SHA-1: 9b67404cbc28a2233eb53efa29ce3f9bd48f6e9f SHA-256: b4443e6458497f82861cba7a7cc020b3e79c38279e47a70c37ee66fe4ac25cfb
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which are part of a link farm, suggesting an attempt to direct users to potentially harmful sites. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to obscure the true destination or spread malicious links across many domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://liga-stf.ru/i/upload/files/xigigizewagaritipibonuxij.pdf In PDF document text
    • http://ingmontagna.com/userfiles/files/40741553810.pdfIn PDF document text
    • http://gachmenminhchien.com/media/ftp/file/86350621648.pdfIn PDF document text
    • https://hram-uspeniya.ru/ckfinder/userfiles/files/2454561098.pdfIn PDF document text
    • https://rh-h1tapi-turbo.com/contents/files/rulalajakimebolufizutaror.pdfIn PDF document text
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/4171a31468e2aab1acf8c73af39b9615/47066278173.pdfIn PDF document text
    • http://patroha.hu/file/27395105374.pdfIn PDF document text
    • http://moveworldtogether.com/datas/files/defipowezuwezalatipag.pdfIn PDF document text
    • http://toyotarent.kr/FileData/ckfinder/files/20210904_03CE0CA22E574152.pdfIn PDF document text
    • http://suvagcentr.ru/userfiles/files/kiwofolazawozapo.pdfIn PDF document text
    • http://unicorn-furnitures.com/d/files/79211203144.pdfIn PDF document text
    • http://healhumanity.foundation/userfiles/file/40057584336.pdfIn PDF document text
    • http://metamorfoza-krosno.pl/userfiles/file/64376252018.pdfIn PDF document text
    • http://happy-land.hu/editor_up/fafegunabinuf.pdfIn PDF document text
    • http://aire-limpio.com/img/editor/file/zogemulijuzosuraw.pdfIn PDF document text
    • http://ieeepes-thailand.org/app/webroot/files/files/barenofenuravapuvo.pdfIn PDF document text
    • http://zulassungsservice4you.de/bilder/file/16937379253.pdfIn PDF document text
    • https://mwasafat.com/uploads/files/pezakiguratugagewobiwuwu.pdfIn PDF document text
    • http://foto-recepty.sk/images/fotky/mijogidojenoxovugunepofa.pdfIn PDF document text
    • http://ortopediaszombathely.hu/editor_up/79725895073.pdfIn PDF document text
    • https://girl0229960192.com/upload/users/files/vimokurasubezi.pdfIn PDF document text
    • https://cvsc.co/userfiles/file/zorilogofuroremasuz.pdfIn PDF document text
    • https://viscom.bg/uploads/wysiwyg/files/tubabebemizobaju.pdfIn PDF document text
    • http://tai-group.com/upload/files/99198707168.pdfIn PDF document text
    • http://avtokit116.ru/!upload/files/memuwob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=watch+it+chapter+2+free+online+englishPDF 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_off0000dc86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC86 10872 bytes
SHA-256: 2a52bf56c9899663e8aad224bf7d109cdbce6e8821172ad3cbcaf3170f9c8aad
font_01_sfnt_off0000f5b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5B6 16416 bytes
SHA-256: 44ee3114ce0ecb7aa06c4ae5d18acb348817a6fb10ea664f9c54fa99fb4430d1
font_02_sfnt_off00012022.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12022 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1