Malicious PDF — malware analysis report

Static analysis result for SHA-256 3d79ecd8fed20fbc…

MALICIOUS

PDF

82.0 KB Created: 2021-09-16 18:06:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: b5fc177066cbe4c6edb91f315c522c23 SHA-1: 57b91acb0249228266543d06039a6b3252e73312 SHA-256: 3d79ecd8fed20fbcba3faa9d1c361eec2a95acec0bacf4cceeebf1fb33db1dcb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to compromised websites and disposable hosting, suggesting it functions as a link farm to redirect users to malicious content. The presence of PDF-specific heuristics like 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this analysis.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://webspace.mysdam.net/images/newsletter/files/kejew.pdf In PDF document text
    • https://macauroommate.com/ckfinder/userfiles/files/jojewefasik.pdfIn PDF document text
    • https://dynasty888.com/image/files/20210905_093040.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16143149a368d2---56394642947.pdfIn PDF document text
    • http://soskuwait.com/outscapes/admin/ckeditor/uploads/ck/files/5866363018.pdfIn PDF document text
    • https://peisheng.org/uploads/ckfiles/files/6136f18cc688c.pdfIn PDF document text
    • http://stowarzyszeniemalyksiaze.eu/img/upload/files/3775693011.pdfIn PDF document text
    • http://balmybnb.com/t/tutorfirm/uploads/ck/files/50863292823.pdfIn PDF document text
    • https://aslplastic.com/ckfinder/userfiles/files/godofobuzufe.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/b83fb403d53247ce137b7001c6112d62/merakiluwimesadejetezaw.pdfIn PDF document text
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/h07sp3jvgd75cid74t7q7tfuk6/velibaz.pdfIn PDF document text
    • https://unibel.pl/pliki/upload/file/35081114669.pdfIn PDF document text
    • http://metabolit-plus.ru/files/file/tifav.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/4adqnbduavsd872qu6d3igo23m/gekoruwujojo.pdfIn PDF document text
    • http://poltinik.ru/userfiles/file/84218852455.pdfIn PDF document text
    • http://sieuthihatgiong.vn/webroot/img/files/41122838594.pdfIn PDF document text
    • http://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/ptit09r3uvn9ev9m72qthtbsb7/dibaka.pdfIn PDF document text
    • http://owv-sad.de/userfiles/files/wamekojorujan.pdfIn PDF document text
    • http://basketaci.cz/UserFiles/File/66054774872.pdfIn PDF document text
    • http://pushgroup.lv/userfiles/files/84031843248.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613773a25e790---61027504212.pdfIn PDF document text
    • http://www.peritaonline.es/ckfinder/userfiles/files/5264796190.pdfIn PDF document text
    • http://www.southpointinstitutehowrah.com/admin/uploads/file/jidaputam.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=watch+cruella+online+free+putlockerPDF 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_off0000dbca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBCA 10592 bytes
SHA-256: 17a1c4782f306f0f5d12cffedee1a3197c02e13cc63e6a47602ac0ca82dba69f
font_01_sfnt_off0000f3ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3EF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010c01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C01 18088 bytes
SHA-256: d611aba0211dadf985a368b57f23a03682db6bcbecfdb3363270b15e82563aab