Malicious PDF — malware analysis report

Static analysis result for SHA-256 22b6b42aa0d70942…

MALICIOUS

PDF

73.3 KB Created: 2021-09-13 18:55:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 2e9cf38b1e06080f338312f4e2b71463 SHA-1: 9ae871e93a29447ec60d49b13427ea5d56895bfb SHA-256: 22b6b42aa0d70942e1f8465f6cf6ab205f357bc7c374aa4ae229d57b3f08597a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier and ClamAV detection strongly indicate malicious intent. The PDF contains numerous external links, many hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://coretry.ru/uplcv?utm_term=acute+decompensated+heart+failure+pdf PDF link annotation
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/6afbj0phagcl0jbgp03n1a44k7/19086795139.pdfIn PDF document text
    • http://phrabat.net/UserFiles/File/jipided.pdfIn PDF document text
    • http://remont-etalon.ru/upload/files/80128078418.pdfIn PDF document text
    • https://siemreaptraveltours.com/userfiles/file/47983673780.pdfIn PDF document text
    • http://fsf-vastroad.com/userfiles/file/66361254798.pdfIn PDF document text
    • http://vuatoyen.com/uploads/userfiles/file/46144940236.pdfIn PDF document text
    • https://chingchia.com/uploads/files/202109021251076845.pdfIn PDF document text
    • http://jysfh.com/upload_fck/file/2021-9-13/20210913054956888075.pdfIn PDF document text
    • http://xn--9n2bn9mz3aba29g44r4o0a.kr/fckeditor/userfiles/image/monekigefefelabokimiwisus.pdfIn PDF document text
    • http://eltdb.com/UserFiles/files/zigimow.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/161393d176f480---xosevirupomutega.pdfIn PDF document text
    • https://next-engineering.com/userfiles/files/13119026753.pdfIn PDF document text
    • https://feldmann-spedition.de/pics/userfiles/file/30179213611.pdfIn PDF document text
    • http://gernano.eu/gfx/userfiles/files/nakozedojazumumutov.pdfIn PDF document text
    • http://casavacanzesanvito.eu/userfiles/files/45818206291.pdfIn PDF document text
    • http://studio-rivetti.it/userfiles/files/gijiwonebiviwubew.pdfIn PDF document text
    • http://detskaoptika.cz/ckfinder/userfiles/files/80813752097.pdfIn PDF document text
    • http://hwangtosidae.com/userData/ebizro_board/file/93535855024.pdfIn PDF document text
    • http://dialog-seversk.ru/jsplugins/ckfinder/userfiles/files/79980550680.pdfIn PDF document text
    • https://lexcyberia.com/userfiles/files/20512270334.pdfIn PDF document text
    • http://museodegliarazzimarsala.com/userfiles/files/97435331315.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ee1340febd---17400953067.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_off0000bbcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBCD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d3df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3DF 16648 bytes
SHA-256: 8810daa8cc7d9862a95e11221329c50fd5f9613ad1faee58033aca15d8ff3699
font_02_sfnt_off0000fea4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEA4 10964 bytes
SHA-256: 1f6398ad4d87965a6d8455c60f58bfc32d7e20691d2265817b785cf38cc7e20b