Malicious PDF — malware analysis report

Static analysis result for SHA-256 99d7e9a0980d24a2…

MALICIOUS

PDF

75.6 KB Created: 2021-09-05 19:36:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 7a5cbf717fb25e8383af791e4256e49f SHA-1: 62d036581ba80ba57f322d55edcab522a53ae3f2 SHA-256: 99d7e9a0980d24a273401593ed1092f8f9de16c9d82181bd99ac37b518f9f1aa
156 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to various domains, many of which appear to be compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or distributing further malware. The structure suggests a link farm designed to obscure the ultimate destination or to manipulate search engine results.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://studiocariola.com/userfiles/files/gipofuwujikoden.pdf In PDF document text
    • https://msr-hudsonproperties.com/wp-content/plugins/super-forms/uploads/php/files/47f46ea47879c2b9c42047760c58cdc6/gufun.pdfIn PDF document text
    • http://remont-elektro.eu/archiv/file/51674248056.pdfIn PDF document text
    • http://agnieszkapawlik.com/userfiles/file/89610819074.pdfIn PDF document text
    • http://jaatkinson.com/userimages/86964322433.pdfIn PDF document text
    • http://hungbuloon.com/media/ftp/file/buzupapibiju.pdfIn PDF document text
    • http://studiomuraca.eu/userfiles/files/vazejuboxojuvaji.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/161263724762d9---17306207788.pdfIn PDF document text
    • https://www.aukuras.org/ckfinder/userfiles/files/lotofeduw.pdfIn PDF document text
    • https://asharfilalkulfi.com/ckfinder/userfiles/files/28273957132.pdfIn PDF document text
    • https://kalyna.ua/sites/default/files/userfiles/file/jodivag.pdfIn PDF document text
    • http://christembassydocklands.org/wp-content/plugins/super-forms/uploads/php/files/0a4f3a25e4b77709ff2ec52004a3bc5e/25125691482.pdfIn PDF document text
    • http://giadinhlaurenso.org/upload/files/96226855569.pdfIn PDF document text
    • https://www.nexidia.it/wp-content/plugins/super-forms/uploads/php/files/2ae6aa30865fb9319d6d49e715230b30/5315648949.pdfIn PDF document text
    • https://aquatrustfina.com/userfiles/file/wajimidijadasazerafaji.pdfIn PDF document text
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a43aa9471ad---87370329739.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f5e730905b---ziwefujepil.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/1609fac8645be9---kubizofewagabofakerizu.pdfIn PDF document text
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/3263eb9eb76a6919999aaf77f5825af3/voguz.pdfIn PDF document text
    • http://vizit-k.net/uploads/editor/files/12454098475.pdfIn PDF document text
    • http://rulada.by/upload/editor/files/bidokas.pdfIn PDF document text
    • https://ddc-touggourt.dz/ar/files/42458125110.pdfIn PDF document text
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073c56e6727e---rimizapukesudop.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607a43be27e99---85259759351.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=cambridge+checkpoint+science+coursebook+7+worksheetsPDF 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_off0000c426.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC426 11416 bytes
SHA-256: 1ef76e58cc65a69452fb19489e247eb812f69725eb97db7ba13fae236c27da45
font_01_sfnt_off0000de99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE99 16340 bytes
SHA-256: c980fc831e1c7dfb39aec1a278d0562bc1616fceb5494607eaebd8c4500b15e4
font_02_sfnt_off00010864.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10864 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1