Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1d8604468ae8953…

MALICIOUS

PDF

71.3 KB Created: 2021-09-30 21:16:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: b3ed5428fc7844b5f312531e1cf73655 SHA-1: 869687341f60e8c16636b06fd1d7b82d48bfee78 SHA-256: f1d8604468ae895303be78ededa5145bc0478aa6f97c4bf558a371305373cb09
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to potentially malicious PDF files hosted on various domains. Heuristics indicate it's a link farm on disposable hosting, and ClamAV detected it as a phishing trojan. The ML classifier also flagged it with high confidence. While no scripts were explicitly extracted, the structure and URL distribution suggest an intent to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 http://issaproject.com/app/views/panel/ckfinder/userfiles/files/rinugotojoriwiwim.pdf In PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/c0666d9dbf4874368b72708da47b359d/38048294824.pdfIn PDF document text
    • http://arcomproltd.com/userfiles/file/nususa.pdfIn PDF document text
    • http://ezclasssites.com/var/wwww/dev-ezclasssites-com/data/files/zirisoroxem.pdfIn PDF document text
    • http://msiutilities.biz/documents/15702040298.pdfIn PDF document text
    • https://alasclub.gr/neuro/ckfinder/userfiles/files/kejibegojevuritegekevep.pdfIn PDF document text
    • http://sqc.jp/user_data/editor/ckfinder/core/connector/php/upload/files/vudupas.pdfIn PDF document text
    • https://hygradeinsulators.com/images/uploads/file/94538813977.pdfIn PDF document text
    • http://berallebags.com/UploadFiles/FCKeditor/20210925022807.pdfIn PDF document text
    • http://partiaweb.ir/upload/files/15811919411.pdfIn PDF document text
    • https://fiscalonline.eu/app/webroot/files/userfiles/files/79972664529.pdfIn PDF document text
    • http://pileshoppen.dk/userfiles/file/jogulivamotilatexam.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/28e97944669ae0057ad65a37a960a396/9669254394.pdfIn PDF document text
    • https://pinyardim.com/calisma2/files/uploads/95297958837.pdfIn PDF document text
    • https://repare-ton-smartphone.com/userfiles/file/13753766361.pdfIn PDF document text
    • https://fotobolfestmeny.hu/mvc/userfiles/file/japeladotakug.pdfIn PDF document text
    • http://worldcar.jp/userfiles/files/zelegotizavobim.pdfIn PDF document text
    • http://henanshuangxin.com/d/files/69963873916.pdfIn PDF document text
    • https://derya.afmiletisimajansi.info/resimler/files/61700915161.pdfIn PDF document text
    • http://kerekagy.hu/UserFiles/file/96144769890.pdfIn PDF document text
    • http://gamebonda.com/ckupload/files/todexe.pdfIn PDF document text
    • https://pharmnet.cz/ckfiles/files/files/83922484513.pdfIn PDF document text
    • https://skatrip.com/basefile/skatripcom/files/wudikuzikipazidividu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=automatic+clicker+app+for+androidPDF 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_off0000b33e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB33E 16972 bytes
SHA-256: 4531ff2eb8dc3cf000e9feab1493b42b4b43acaf4cd35ab2abcfce795089494b
font_01_sfnt_off0000de7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE7C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f693.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF693 10788 bytes
SHA-256: 71cd2f8194438db7c234f7b5822cda248b656ed1d4f37f5d36ac0ada1d526821