Malicious PDF — malware analysis report

Static analysis result for SHA-256 d1423ab3d7b734f5…

MALICIOUS

PDF

85.0 KB Created: 2021-07-26 03:24:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 35b55305df1cfcb4beeca2033eed28fb SHA-1: 283087d1b8180116cb924fce8bae932ec1ed88d0 SHA-256: d1423ab3d7b734f5cd8eb9f4ea51d9f8bfd2b02438885af6710e73b5079d6c27
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to compromised WordPress uploads and disposable hosting. These links likely serve as lures for phishing or to distribute further malware, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/82462784c5b37fccaa11c47919dba631/gulagonebajaxolo.pdf In PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/160ad0e950aca5---92654193200.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607ada896c523---jugiwimefazeresemuwelu.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160bccb425ed55---tolipowudumukutadiriwawa.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ddd323ea236---29780822298.pdfIn PDF document text
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/67855865814.pdfIn PDF document text
    • https://ises.ca/phpsites/vertical_living/uploads/file/xifet.pdfIn PDF document text
    • http://rauvuonsach.com/images/uploads/files/gevowaf.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d89331513a---zemiv.pdfIn PDF document text
    • http://tvoirostov.ru/ckfinder/userfiles/files/84545164713.pdfIn PDF document text
    • https://istocdukkan.com/userfiles/files/13411563770.pdfIn PDF document text
    • http://dansungsala.com/uploads/files/19441792223.pdfIn PDF document text
    • http://dui-antidote.net/images/userfiles/file/53034260035.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609aacba379b0---62291582459.pdfIn PDF document text
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/8497e1de7a949068418e7c2eede75422/36281342734.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16081d93900c38---dixenikulegaxuposibupudex.pdfIn PDF document text
    • https://playerpress.com/ckfinder/userfiles/files/54683884113.pdfIn PDF document text
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/rfhtu8qfg1nk86bdmuopq8nu65/26865364455.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607171df7862f---mebebatigep.pdfIn PDF document text
    • http://enjoy.sk/editor_uploads/system/files/goruwajikixuxofe.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c074a40a851---sefosinelipafoto.pdfIn PDF document text
    • https://divinenine.net/userfiles/file/toxapuwazo.pdfIn PDF document text
    • https://forex-robo.org/wp-content/plugins/super-forms/uploads/php/files/52ca633f68296df6d207cfa8a05baa74/12820208134.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/jceaqee94un79ldnhuge3tiina/gikura.pdfIn PDF document text
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abf1036e972---25030147119.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=install+autocad+2008+on+windows+7+32+bitPDF 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_off0000e54b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE54B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fd62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD62 11080 bytes
SHA-256: 69de4e9dcf23892c801e5499eaea3f71510cacc9874ae691e4aef853dca692d0
font_02_sfnt_off00011781.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11781 17844 bytes
SHA-256: 7b4a6a12d48197074866f1ed1eda8549c6290b636a8b345351a8a59a16c83550