Malicious PDF — malware analysis report

Static analysis result for SHA-256 81c5a8f21030de44…

MALICIOUS

PDF

87.3 KB Created: 2021-09-07 16:26:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: e29bb542dd4f3a3e1ca47fa9638b5326 SHA-1: 1ef9e574a0ab1c63da03870fc6bb7b23d8b02c0f SHA-256: 81c5a8f21030de440ffaeae8adf3b6775e0fbc616608530112a20dce67235027
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for delivering malicious payloads or redirecting users to phishing sites. The presence of numerous external links, many hosted on compromised WordPress sites, further supports a phishing or malicious content delivery attack pattern. The ClamAV detection and ML classifier strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://geodez.com/pliki/file/4585730011.pdf In PDF document text
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/864590d1e9b6858e11d39709a42fca39/63272110768.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/17c84225a917563c672290e6d985452b/bizevo.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/t740eacdl28m5jpknt0095rp84/66379271706.pdfIn PDF document text
    • http://anthonyvienna.com/sites/default/files/file/rigitufelugigexijike.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16090f8a7b453a---46719623414.pdfIn PDF document text
    • http://hotararicedo.ro/files/files/domuverizamojirozamuxu.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161114eab2155a---68548111499.pdfIn PDF document text
    • http://danieldesignpro.com/userfiles/16405040053.pdfIn PDF document text
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/t869fmgm2dhu5ebflqbh252bjl/2935862540.pdfIn PDF document text
    • https://jxloanchien.com/style/postimage/file/1518157126.pdfIn PDF document text
    • https://www.rongoldmanlaw.com/system/js/back/ckfinder/userfiles/files/73937397281.pdfIn PDF document text
    • http://ausafe.net/images/art/files/sevonajoliredezip.pdfIn PDF document text
    • https://aedwea.com/upload/foto/69551004942.pdfIn PDF document text
    • https://baoholaodong24.com/userfiles/file/90913326329.pdfIn PDF document text
    • https://useoneconvo.com/wp-content/plugins/super-forms/uploads/php/files/7b87db33c8a01bf42a12a50c50d93328/40657137365.pdfIn PDF document text
    • https://bimetoor.com/basefile/bimetoorir/files/2787098600.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/c74e4eccab21a998a1d92716d859b7ef/68667428570.pdfIn PDF document text
    • http://chalappuram.com/userfiles/file/gakekesaguzevujem.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/16224823679.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/3998e38e1019114e23973102bb35fd1a/63468784638.pdfIn PDF document text
    • https://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/5cae5c4065ca51df506363352812ae10/jobafibatigiworok.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607bb251cc263---91728897727.pdfIn PDF document text
    • http://urdu-hadith.com/survey/userfiles/files/2304720098.pdfIn PDF document text
    • https://lescourailleurs.com/upload/editor/file/65184939777.pdfIn PDF document text
    • http://messtores.ca/fck_user_files/file/vubap.pdfIn PDF document text
    • http://sns-russia.ru/userfiles/file/84733792439.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=print+calendar+pdf+2019PDF 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_off0000ead9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAD9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000102eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102EB 19704 bytes
SHA-256: 2f6312a3083ffac254752b61835323fe60047804fe09dfeb1bb29b523851f1a5
font_02_sfnt_off000135f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135F1 10788 bytes
SHA-256: 3846a9611b3367530aa67ac7a8f9cdc02c5e988a84e40c8a39407745b96011a0