Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1166166b6eb77e1…

MALICIOUS

PDF

81.5 KB Created: 2021-09-17 22:28:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: afb2bcd408331a8c5d844c674bc08ee1 SHA-1: 930dd946199375ea8f36f2609302d7b41199800d SHA-256: b1166166b6eb77e13e78dd20e6abd50d3914ea5ed56c5c8312ac4a4da0a5c005
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these external links. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://archism.ru/uplcv?utm_term=1und1+mail+app+android PDF link annotation
    • http://kdbelektrotechniek.nl/uploads/file/75127700085.pdfIn PDF document text
    • https://hotararicedo.ro/files/files/73725169632.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/161413b4491636---53330449891.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161403b323922e---8205706797.pdfIn PDF document text
    • https://es21sys.com/userfiles/file/22566519528.pdfIn PDF document text
    • https://brillimet.com/uploads/files/202109071027316751.pdfIn PDF document text
    • http://sourceit.ke/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/21685339243.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/38a4b91c1f53fbc478e75420a3d48504/piwimav.pdfIn PDF document text
    • https://costarica4d.com/contents/files/18886671050.pdfIn PDF document text
    • https://sma-dfgg.org/site/admin/file/gajowurevanekewoxot.pdfIn PDF document text
    • http://kvarkeno56.ru/userfiles/file/8857901363.pdfIn PDF document text
    • http://lavalnerina.it/userfiles/file/lesared.pdfIn PDF document text
    • https://fix2go.info/userfiles/file/saxijefora.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16143607646d54---62338384492.pdfIn PDF document text
    • http://shahnawazonline.com/uploads/files/62112675607.pdfIn PDF document text
    • https://siriusdynamics.com/assets/uploads/files/86463274352.pdfIn PDF document text
    • http://www.dr.schure.net/ckfinder/userfiles/files/73406458875.pdfIn PDF document text
    • https://tidurmalam2.com/contents/files/26276884718.pdfIn PDF document text
    • http://irvinenott.co.uk/ckfinder/userfiles/files/64499530871.pdfIn PDF document text
    • http://duancanhotot.com/upload/files/41979619556.pdfIn PDF document text
    • http://luchetti.it/userfiles/files/55263777448.pdfIn PDF document text
    • https://inprovitbrasil.com/ckfinder/userfiles/files/xajotukulo.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_off0000dd44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD44 10208 bytes
SHA-256: 8b538a186de50d71117b6ff81e1fba03b20c767663150442b1fa893b4de9e24b
font_01_sfnt_off0000f3f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F7 17244 bytes
SHA-256: 24fa9240d42eb07014af31544cfa4b1464420c097b7e52f35366544bb0d20244
font_02_sfnt_off000120d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120D0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1