Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5d16567bc10939d…

MALICIOUS

PDF

83.7 KB Created: 2021-09-10 06:00:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 9f3050bdcff6137044202fabd976d173 SHA-1: e2c669bde5d4186ef25195c9924673f3750b8e98 SHA-256: c5d16567bc10939d08d33f5d088a83197d87d7082bb191120eef365cb3fe81f6
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests it functions as a link farm, directing users to numerous distinct, potentially disposable hosts. While no scripts were explicitly extracted, the presence of embedded URLs and the overall structure point towards a phishing or malware distribution scheme, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://tanthueviet.vn/img_data/files/tokope.pdf In PDF document text
    • http://change4best.ru/upload/file/todojur.pdfIn PDF document text
    • http://ticaproduce.com/ckfinder/userfiles/files/jefujokewa.pdfIn PDF document text
    • http://vevo.keresztessyoptika.hu/elemek/file/dubufapupuje.pdfIn PDF document text
    • http://skulpt.in/admin/uploads/file/tizareworijivonawotuziruw.pdfIn PDF document text
    • http://greece-ex.com/images/blog/file/jumufavodudeseze.pdfIn PDF document text
    • http://www.weilandensemble.nl/ckfinder/userfiles/files/3822948981.pdfIn PDF document text
    • https://bagstyle.uz/images/file/xapebajawawupilaronevel.pdfIn PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161364f301d209---sifaratos.pdfIn PDF document text
    • https://dalton-english.com/userfiles/file/kikejo.pdfIn PDF document text
    • http://guide-eq.com/userfiles/file/20210910070352_bzmnrz.pdfIn PDF document text
    • http://bobhendrix-law.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dagogepinumesuxagefojax.pdfIn PDF document text
    • http://avtokapriz42.ru/userfiles/file/dowetibolizuxalofa.pdfIn PDF document text
    • http://appinaris.net/ckfinder/userfiles/publics/files/3218365576.pdfIn PDF document text
    • https://suacuacuontoanphat.com/upload/files/67232778246.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/2bb70117b1fcdd3899ff9e26aa606821/28386082620.pdfIn PDF document text
    • http://elistaprezentow.pl/userfiles/file/75423904624.pdfIn PDF document text
    • http://serdceprirody.ru/userfiles/file/59782411891.pdfIn PDF document text
    • http://bangdientunhk.com/upload/files/52679236287.pdfIn PDF document text
    • https://olterus.net/contents/files/jeperamukimurekopabaki.pdfIn PDF document text
    • http://www.jobsincrete.gr/images/_user_na/file/zokadavipigemazog.pdfIn PDF document text
    • https://ashleymongolia.mn/uploads/files/82463020128.pdfIn PDF document text
    • https://adtw1.elfjane.com/ckfinder/userfiles/files/20467847627.pdfIn PDF document text
    • http://diagnosticaedilizia.com/userfiles/files/xixepikisari.pdfIn PDF document text
    • http://haokunchem.cn/upload/files/ripatujifaxumalewa.pdfIn PDF document text
    • https://conexkarvan.com/cache/fck_files/file/25214504511.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=chal+mera+putt+2+online+movie+freePDF 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_off0000de97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE97 10772 bytes
SHA-256: a775d099c1d1b76f5ea2f34e718eaa9c9c4e7ba12ef91f3f2ab9b34cae409177
font_01_sfnt_off0000f73a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF73A 19128 bytes
SHA-256: 1e725187d2683e77c6642aaaf26de0a67ec96f929c4344065565ea6c422a8e1e
font_02_sfnt_off000128db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128DB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1