Malicious PDF — malware analysis report

Static analysis result for SHA-256 544f483764d65bff…

MALICIOUS

PDF

79.8 KB Created: 2021-09-27 11:15:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: df5a8d0487662daf09c2e21904b87129 SHA-1: 86c6c3d82d4bbd9bae11674ad0ad0d888941fce0 SHA-256: 544f483764d65bff856ebeb1cf99f64b4d008182af3b954ad65e2c3003b376c0
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which are part of a link farm hosted on disposable domains, suggesting a phishing or redirection attempt. The file's metadata indicates it was generated by wkhtmltopdf, a tool often abused to create malicious PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9781

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://laborke.ru/uplcv?utm_term=faster+youtube+video+downloader+for+android PDF link annotation
    • https://knurussian.kr/DATA/upload/files/202109050731214383.pdfIn PDF document text
    • http://happinessgown.com/upload/users/files/mamuloginunewagetepavalas.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141692a5c66d---joxozomusidenevur.pdfIn PDF document text
    • http://bilcafe.it/userfiles/file/20387722779.pdfIn PDF document text
    • https://leanuslab.com/UserFiles/file/zakilajagobekibij.pdfIn PDF document text
    • https://medpressa.ru/files/file/76547711066.pdfIn PDF document text
    • http://jafra-com.at/userfiles/file/83558582210.pdfIn PDF document text
    • http://gazomotor.com/allinone/file/fuvodifid.pdfIn PDF document text
    • https://lentes123.com/aym_image/files/nezepi.pdfIn PDF document text
    • http://dellalontra.it/userfiles/files/ladolalerilukorimo.pdfIn PDF document text
    • http://checopharma.com/upload/files/pobafazowopefafidiviw.pdfIn PDF document text
    • https://chuyennhakienvangvn.net/upload/files/17176935654.pdfIn PDF document text
    • http://cheapstandard.com/uploads/files/nemenokodufilijoz.pdfIn PDF document text
    • https://smgbid.com/ckfinder_userfiles/files/24086429128.pdfIn PDF document text
    • https://tavfelugyelet.megujuloenergiapark.hu/admin/ckfinder/userfiles/files/sasifab.pdfIn PDF document text
    • http://apartament-krokus.pl/userfiles/file/16738872841.pdfIn PDF document text
    • https://il-gusto.com/images/file/19398888236.pdfIn PDF document text
    • http://tomboy2.com/images/library/File/pusodeguwalaxoxun.pdfIn PDF document text
    • http://refinerlink.com/userfiles/file/pexigivilov.pdfIn PDF document text
    • http://alt-1c.ru/userfiles/file/xobalinurasagesokozig.pdfIn PDF document text
    • http://xueyuan.zlyxgw.com/uploads/ckeditor/files/20210921075956.pdfIn PDF document text
    • http://szhlfz.net/upload/49901600630.pdfIn PDF document text
    • http://helicopterleasingservices.com/userfiles/files/zerugoregeronexixivunuj.pdfIn PDF document text
    • http://chinamakina.com/userfiles/file/54432953866.pdfIn PDF document text
    • https://viboot.com/ckfinder/userfiles/files/pirare.pdfIn PDF document text
    • http://softtox.com/new/userfiles/file/3200094404.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b651.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB651 19300 bytes
SHA-256: 6c928149457589b2f7541b910fdc47df2beb3f6ddc49901b0e0f3c90da1dd6b2
font_01_sfnt_off0000e817.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE817 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010028.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10028 16188 bytes
SHA-256: 800554d3d6320da9c8ab21a3ad3d270f40e7a92360d7538c059d647d952d1d34
font_03_sfnt_off000115df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115DF 10828 bytes
SHA-256: b81782f234363ce24d21e9f55a0f79d0cfa7fcd23d18891b256f720d09f44d7b