Malicious PDF — malware analysis report

Static analysis result for SHA-256 37ff729e911f5f42…

MALICIOUS

PDF

79.4 KB Created: 2021-10-05 04:04:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 2cd0166c430c61e50a82013ca16d5edc SHA-1: 6b7288675c2c76bd2be6a4f8fa7a625a23701de3 SHA-256: 37ff729e911f5f422a2ebfdbd0794e1097f1942b81d8a64f270fdd16e2446a86
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by multiple heuristics, including a critical ClamAV detection and an ML classifier. It contains numerous external URLs, with one heuristic specifically identifying it as a link farm on disposable hosting. The PDF structure and embedded URLs suggest an attempt to redirect users to potentially harmful websites, aligning with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://crysiq.ru/uplcv?utm_term=foolproof+answers+module+8+burning+money PDF link annotation
    • https://www.displaysdirectaustralia.com.au/application/third_party/ckfinder/userfiles/files/datafewenixonitajite.pdfIn PDF document text
    • http://risme.vn/files/wakobolitugusizewex.pdfIn PDF document text
    • http://kppzp.pl/userfiles/file/nomepafijobexolifetov.pdfIn PDF document text
    • http://cgmorenanews.com.br/ckfinder/userfiles/files/lijatumazolexesig.pdfIn PDF document text
    • http://saipanbooking.com/FileData/ckfinder/files/20210923_B9CD01FA1C468199.pdfIn PDF document text
    • http://robedecreateur.com/img/files/lolitolufimubes.pdfIn PDF document text
    • https://gesema.com/UserFiles/file/92227310259.pdfIn PDF document text
    • http://fatfailogistics.com/fckeditor/files/file/3144765967.pdfIn PDF document text
    • https://mmeasar.com/mmeasarfiles/file/71717034613.pdfIn PDF document text
    • https://ana-jsc.com/upload/files/xidepabojeberoxexixomewil.pdfIn PDF document text
    • http://wu-pao.com/upfiles/editor/files/69075732957.pdfIn PDF document text
    • http://mateuszkucharski.pl/admin/file/gebalafedoxesavinova.pdfIn PDF document text
    • http://bhk-aindling.com/userfiles/files/45214058108.pdfIn PDF document text
    • https://adci.vn/data/upload/file/60325838912.pdfIn PDF document text
    • http://anabakorea.jp/userfiles/file/39972148781.pdfIn PDF document text
    • http://nage-z.com/ckfinder/userfiles/files/tawejaweloguvadezur.pdfIn PDF document text
    • http://teleinwestor.com/userfiles/file/92686385113.pdfIn PDF document text
    • http://kstarsmall.net/userfiles/file///84807796566.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142aa872c990---wokomesotatara.pdfIn PDF document text
    • http://anhuicrew.com/upload_fck/file/2021-9-16/20210916104947390120.pdfIn PDF document text
    • https://tuyendung.vinaonegroup.net/upload/files/86600457174.pdfIn PDF document text
    • http://theexplorerthai.com/userfiles/files/sekovikapa.pdfIn PDF document text
    • http://dharmapuridiocese.com/svnprojects/DHD/Source/images/files/rerudijapanon.pdfIn PDF document text
    • https://12shio2.com/contents/files/pifetivoboliwebimo.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_off0000c91b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC91B 11368 bytes
SHA-256: e9aad5054d84fe52b27d584abb3ca2a055cfd9d790d2f049da167d2a5a5e1935
font_01_sfnt_off0000e379.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE379 20512 bytes
SHA-256: 6bf8901d3603a28dc467bd90463a1ef698c300e2ac8dcd90f13fe1d38c47cb42
font_02_sfnt_off0001177c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1177C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1