Malicious PDF — malware analysis report

Static analysis result for SHA-256 a84bcd341e1f7012…

MALICIOUS

PDF

87.7 KB Created: 2021-09-18 18:49:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 585d937706a5db35f02ad059b1729764 SHA-1: 4da420f435adaf4a574244a9b3ec73e3f7c6a282 SHA-256: a84bcd341e1f7012bee6bdd17e7790e622a43fc2af4bef3997c58c537c938c15
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many pointing to compromised or disposable domains, indicative of a link farm designed to lure users to malicious sites. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this phishing or malware distribution intent. The ML classifier and ClamAV detection further confirm its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://synerhu.ru/uplcv?utm_term=how+to+put+sim+in+android+phone PDF link annotation
    • http://secureyun.cn/uploadfile/file///2021090314474942.pdfIn PDF document text
    • https://aquafilling.com/userfiles/file/40013616699.pdfIn PDF document text
    • http://intimatehotelpattaya.com/image/upload/File/ribeteboxasi.pdfIn PDF document text
    • https://cuatudongsaigon.net/uploads/files/45246849039.pdfIn PDF document text
    • http://articolo17.it/siti/usr/foto/files/zadabagawub.pdfIn PDF document text
    • http://xn--90aoaidn.xn--p1ai/ckfinder/userfiles/files/91136785155.pdfIn PDF document text
    • http://dalboncostruzioni.it/userfiles/files/gerilifibigirif.pdfIn PDF document text
    • https://detectiveoffice.net/userfiles/file/26661538952.pdfIn PDF document text
    • http://lideparts.com/userfiles/file/1631897615.pdfIn PDF document text
    • http://bretagne.annuaire-regional.com/ckfinder/userfiles/files/molone.pdfIn PDF document text
    • http://ieltsadd.ir/cache/fck_files/file/kebegekejamibitiwazixigij.pdfIn PDF document text
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/c9bf70b9c705ac65d862d3aed6a7c6d1/gepebupesogelovu.pdfIn PDF document text
    • http://www.goldenlantern.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1614424540b81f---dawovibep.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16137be1dd797e---38745303253.pdfIn PDF document text
    • https://mimpishio2bet.net/contents/files/fibarut.pdfIn PDF document text
    • https://comfortinnbarrie.com/phpsites/vertical_living/uploads/file/dudilenipasirepizamiwu.pdfIn PDF document text
    • http://gorsilawfirm.com/userfiles/file/42881616613.pdfIn PDF document text
    • http://cck-brno.cz/ckfinder/userfiles/files/97404785624.pdfIn PDF document text
    • http://e-park.es/img/uploads/files/vojizalodovekip.pdfIn PDF document text
    • http://ducthanggroup.com/webroot/img/files/42026572908.pdfIn PDF document text
    • http://caudafotografia.com/userfiles/files/segedufejimutu.pdfIn PDF document text
    • http://spodne-pradlo-2bpoint.sk/UserFiles/File/tokeso.pdfIn PDF document text
    • http://sdds.be/userfiles/file/nivaparetaw.pdfIn 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://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_off0000f209.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF209 10788 bytes
SHA-256: cc13744abd4a232ab21ac8653fdd79955f258cf9b087182bd73ee5f4c05dff72
font_01_sfnt_off00010ab1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AB1 17808 bytes
SHA-256: 4258035bfa96db66fb2b709acb5c54590093e0100b0dd4441bf97d3403d643de
font_02_sfnt_off000138fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x138FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1