Malicious PDF — malware analysis report

Static analysis result for SHA-256 57b5b15644b1afe8…

MALICIOUS

PDF

86.8 KB Created: 2021-09-17 01:04:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: cf645bb8c99181d5176d1d4e149ae6ea SHA-1: 992d2abd19c67f9601721da8059537e69dd1ef44 SHA-256: 57b5b15644b1afe85796c17d6c191b6c70562697a6a34d1919df5e096c3d0c60
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document contains numerous links to disposable hosting, suggesting an attempt to distribute malicious files or conduct phishing. The presence of a 'download button' heuristic further supports a lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://xn--80adpfaaeictf0c6c7i.xn--p1ai/public/file/75793622055.pdf In PDF document text
    • http://www.amedna.com/userfiles/files/zinoluwojukawirosagidoba.pdfIn PDF document text
    • http://tugrabilgisayar.net/resimler/files/fizatumekadoxixofigogipex.pdfIn PDF document text
    • http://morpheus-architects.com/file_media/file_image/file/27537892634.pdfIn PDF document text
    • http://greenbiotech.vn/uploads/userfiles/file/puzokukodoxat.pdfIn PDF document text
    • https://leise.ru/admin/ckfinder/userfiles/files/47609490117.pdfIn PDF document text
    • http://musthighschool.mn/ckfinder/userfiles/files/58401095189.pdfIn PDF document text
    • http://uptindia.com/newsimages/file///zufusopitaf.pdfIn PDF document text
    • http://fuhua.tumujike.com/assets/upload/files/202109060030138893.pdfIn PDF document text
    • https://burgaseguros.com/userfiles/file/ludijen.pdfIn PDF document text
    • http://phelieuviethung.vn/upload/files/zoboxe.pdfIn PDF document text
    • http://anticacarsulaeborzoi.eu/userfiles/files/fuvonegide.pdfIn PDF document text
    • https://ingatlansos.hu/images/userfiles/file/73343874106.pdfIn PDF document text
    • http://dotbamboo.com/file_media/file_image/file/16862144285.pdfIn PDF document text
    • http://webinaris.org/ckfinder/userfiles/publics/files/90076117850.pdfIn PDF document text
    • http://sampoernastrategic.com/uploads/image/files/nefifamagipabe.pdfIn PDF document text
    • http://www.astmalek.cz/obrazky/file/wafuxaxoviwatiku.pdfIn PDF document text
    • http://giteduguedesboires.com/userfiles/file/53645541263.pdfIn PDF document text
    • https://bomberosdenavarra.com/userfiles_nexo/files/dapisufejorelilod.pdfIn PDF document text
    • http://inteko-tula.ru/f/file/rekugonulaw.pdfIn PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fb1e2bdaa0---joseluduwu.pdfIn PDF document text
    • https://mvmdigital.gr/files/files/lalaxomokivubosinorafigid.pdfIn PDF document text
    • http://aquaclub.hu/userfiles/file/63627813498.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=optics+5th+edition+hecht+solutions+manualPDF 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_off0000e788.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE788 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ff9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF9A 19404 bytes
SHA-256: ca320a30b97642297343e5ef19286a392d9148d278fbda7808f857adad1d0733
font_02_sfnt_off00013305.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13305 10940 bytes
SHA-256: 73eef9d3a66eee362aa5c3fe9ced2057b9683167d89dd44b33c64449a1031865