Malicious PDF — malware analysis report

Static analysis result for SHA-256 c81e6237abf1d59c…

MALICIOUS

PDF

62.4 KB Created: 2021-10-21 09:14:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: a7074822ccb99251c5bf33dc688814f8 SHA-1: 84fedb34e460f837eee8ec7a66c2c22e3b556554 SHA-256: c81e6237abf1d59c3deb895b3c18be3aa45bce433689919b7e64e0745aa51968
154 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating it is likely a phishing or malware distribution attempt. It contains numerous embedded URLs, many of which point to potentially compromised websites or disposable hosting, suggesting a link farm designed to redirect users. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this conclusion.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6412

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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
  • 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://tsolisp.com/files/file/2807928240.pdf In PDF document text
    • http://x-mobio.com/upload/files/9107381038.pdfIn PDF document text
    • https://highfieldhousehotel.net/nbloom/fckuploads/file/jisavoxivazekakok.pdfIn PDF document text
    • https://ddshower.com/ckfinder/userfiles/files/42703356925.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/e374vnd6q1837sj8ilc2sfk6g2/66926139999.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/1616a22df3778e---fokibajuxebix.pdfIn PDF document text
    • https://www.lavishlook.se/wp-content/plugins/super-forms/uploads/php/files/b4794120b119f07afecbbf06763209f6/levezebif.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/cc5bbe0adafbb639ef44b8d9d7b70530/83012257359.pdfIn PDF document text
    • https://mimpishiosatu.com/contents/files/zalujaguzatesuwuvapapem.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/u4n6sst49c6ehr5ev17qpvs5d5/rituvugoloxisisif.pdfIn PDF document text
    • https://chiataiec.com/userfiles/Proj_Name/files/60713865949.pdfIn PDF document text
    • http://bilafafafa.com/shopadmin/upload/files/varajudanev.pdfIn PDF document text
    • http://www.anclupnapoli.it/userfiles/file/salesunimojumuxop.pdfIn PDF document text
    • http://www.oe.com.tw/ezadmin/ckfinder/userfiles/files/36489942670.pdfIn PDF document text
    • http://somsit.com/ckfinder/userfiles/files/menovedewutebuwimokiw.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1616bb98778786---wepatuwivazaxeka.pdfIn PDF document text
    • http://chaodontuonglai.vn/uploads/ck_upload/files/miwuniguwemowabeduxatikar.pdfIn PDF document text
    • http://www.eau-msu.ru/ckfinder/userfiles/files/futimudot.pdfIn PDF document text
    • http://adacu.org/userfiles/file/20210903101829.pdfIn PDF document text
    • https://www.antoniopopolizio.it/ckfinder/userfiles/files/nofuvevafidilakivatet.pdfIn PDF document text
    • http://topenglish.sk/app/webroot/gallery/files/ruzusesezurunexidetenepal.pdfIn PDF document text
    • https://adurucui.com/ckfinder/files/67826515144.pdfIn PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/161639c2627caf---vodadovukowakub.pdfIn PDF document text
    • http://kfnmdg.com/upfolder/e/files/20210919222433.pdfIn PDF document text
    • http://komodovo.ru/upload_picture/pavos.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/7xhmvLXWVJc/uplcv?utm_term=dna+replication+answersPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d338.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD338 16876 bytes
SHA-256: b776b3810516d693b99eb144896c85edc380c2d6b66abd9c31ab0e26081645ca