Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bcb4d3d7ab13925…

MALICIOUS

PDF

77.8 KB Created: 2021-06-11 04:44:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 335d009eaa7cf3e4db9ccd8851a90f17 SHA-1: 05dc8d4a0b50c56262513ce2dfade2b160f296fa SHA-256: 4bcb4d3d7ab13925e8f9289fb6ec6cb24cc183eee68bb347b1e12150c6a15c4e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous URLs pointing to compromised websites and disposable hosting, suggesting a link farm designed to distribute malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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
  • 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 https://allytemp.ru/uplcv?utm_term=chemistry+grade+11+pdf+download PDF link annotation
    • http://humanitool.ru/userfiles/file/36774364478.pdfIn PDF document text
    • https://bonpetsupply.com/wp-content/plugins/formcraft/file-upload/server/content/files/160747cc836bcc---gakolafufaxozetiko.pdfIn PDF document text
    • https://useoneconvo.com/wp-content/plugins/super-forms/uploads/php/files/2baedb4d1ff7032a08180cb0c659e24f/56869944726.pdfIn PDF document text
    • http://agnieszkapawlik.com/userfiles/file/13844727800.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607afa4763225---17086673506.pdfIn PDF document text
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/f548rmj4mq76uqeigtf7gde1m1/94377251069.pdfIn PDF document text
    • https://chefinhogourmet.com/wp-content/plugins/super-forms/uploads/php/files/2d84f75fabd464b5bff4fa55d1d9c2d9/97193505261.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/1606dcf1124148---tubazajoribezulepizavaril.pdfIn PDF document text
    • http://workprohealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094b0a69db0e---4716381778.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/svan25v6dksv4613purkh6fnck/weselufezesi.pdfIn PDF document text
    • http://riskhedgetech.com/uploaded/file/4953607296096283f3b083.pdfIn PDF document text
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/df21ab37ee252cac26477dd982759879/manavut.pdfIn PDF document text
    • https://prtl.pl/userfiles/file/26404868208.pdfIn PDF document text
    • http://grandchainfamilyfoundation.org/clients/85333/File/63598195282.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/8bckooo9hr8odhiv0m9bqjkjee/42181315752.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b244c1c0f40---zoretevijujegarufura.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://fedorahosted.org/lohitIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC52 5608 bytes
SHA-256: cfb62c10660751b2b378d75da54a736cdf2231498a0dfd81d2eadfdb96b92f27
font_01_sfnt_off0000ef52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF52 10524 bytes
SHA-256: 2917be3a9a2bbad02316945ffec814d9d04890a17cdfdb47e11cbd4d419dcce0
font_02_sfnt_off000113a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113A3 5832 bytes
SHA-256: 6b7a4f66a794107f94009e5e639f46ff375d134267c5c204fbf6d0ae10fd715a