Malicious PDF — malware analysis report

Static analysis result for SHA-256 24bffc74dedc69dc…

MALICIOUS

PDF

86.2 KB Created: 2021-09-11 14:27:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: b079c9a93e65fcdd1327f614d56fdf5f SHA-1: c20da7359812f638eba80d8150b42a44f7c19630 SHA-256: 24bffc74dedc69dc864eb342c77a37c4aac01ed9d860a8518078d18b98c3545a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was flagged by multiple heuristics as containing a link farm and potentially malicious content, with a high ML score and ClamAV detection. The embedded URLs and the PDF structure suggest an attempt to redirect users to compromised or malicious websites, likely for phishing or malware distribution. No scripts were extracted, and the document body was unreadable, limiting further analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://brickform.cz/obrazky/files/28498490644.pdf In PDF document text
    • http://stefanourso.com/public/userfiles/file/94248944685.pdfIn PDF document text
    • http://lamekatus.com/uploads/ckeditor/files/pigufosafider.pdfIn PDF document text
    • http://pmke.cz/pictures/files/giteniguj.pdfIn PDF document text
    • https://implantologie-deva.ro/app/webroot/files/userfiles/files/17202260443.pdfIn PDF document text
    • https://sedefartphotography.com/resimler/files/rewanonatutuze.pdfIn PDF document text
    • https://triptoboloyfoundation.org/editorsfiles/files/92039291791.pdfIn PDF document text
    • http://www.casasemio.com.br/ckfinder/userfiles/files/dupefozaneluzaxodo.pdfIn PDF document text
    • https://ukmriptek.org/codeIgniter-hmvc/userfiles/files/46628431870.pdfIn PDF document text
    • https://djennebeads.com/nbloom/fckuploads/file/93375695560.pdfIn PDF document text
    • http://www.cerathai.com/image/upload/File/26578923269.pdfIn PDF document text
    • http://chronocertif.com/userfiles/file/61255755768.pdfIn PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/3452ae27eedf2c5723a1c2501a29acbf/fizovilutexinovinureve.pdfIn PDF document text
    • http://banhangcongnghe.com/upload/FCK/file/68007474404.pdfIn PDF document text
    • https://www.hotelamoha.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613363b90de39---renorofuminisasiz.pdfIn PDF document text
    • http://brandorbit.in/userfiles/file/xivuremaxodu.pdfIn PDF document text
    • https://kaptenhoki.org/contents/files/xarelewi.pdfIn PDF document text
    • https://theurbanthinktank.com/files/40193019962.pdfIn PDF document text
    • http://brmhn.com/userfiles/file/20210904194839_esbnot.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-9-6/20210906002652821574.pdfIn PDF document text
    • http://morakothotel.com/file_media/file_image/file/polimaborotewoxam.pdfIn PDF document text
    • http://aktasmatbaacilik.com/resimlerfiles/vilom.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/4ffa78d37932a4d1dda611f5bd45435f/72675385071.pdfIn PDF document text
    • http://yeongwonenc.com/userfiles/file/57972272687.pdfIn PDF document text
    • http://goodnest.info/tctt/sites/aaa/file/losixub.pdfIn PDF document text
    • https://sysyanginguvenlik.com/uploads/files/fenurasalu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=free+spyware+for+android+phonePDF 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_off0000ec56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC56 17620 bytes
SHA-256: 8a6656c3d78111fa46761a62785aaedd4816ec21c52fb0eb514f77a3b069ba90
font_01_sfnt_off00011a79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A79 10628 bytes
SHA-256: 689e0075eebe135a6160af5b34adafc8f118c511928d6fa98f8740c0014baa84
font_02_sfnt_off000132c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132C7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1