Malicious PDF — malware analysis report

Static analysis result for SHA-256 55ac5daff37778fc…

MALICIOUS

PDF

87.3 KB Created: 2021-09-06 07:52:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 04fd29ed68beeb5111a70b768ad38ba1 SHA-1: 4e57d4327c430fa6072fad9255dc877c385976a8 SHA-256: 55ac5daff37778fc23fbc2f2f509ad96bc2f660613079ec0ca5af223af0413a0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, suggesting a phishing or malware distribution scheme. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of an attack pattern that likely involves redirecting the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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 https://www.agcontraincendios.es//ckfinder/userfiles/files/dogoluriroxejurujefitif.pdf In PDF document text
    • http://raunlarose.us/wp-content/plugins/formcraft/file-upload/server/content/files/160747c5e5f43c---20252513555.pdfIn PDF document text
    • http://zgic.ru/!upload/files/lonidijodijixagaxabo.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608eb73b5fc17---suretusezunitan.pdfIn PDF document text
    • https://birudongker.com/contents//files/70723111127.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/990t57juc7fmrefrcvu40qerj7/41141835211.pdfIn PDF document text
    • http://knoxvillecentralhs1966.com/clients/8/8c/8c0a3a1fea337096d337135aeb812fb1/File/vawozudixigaju.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607b40b7b974a---kunepib.pdfIn PDF document text
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606f9b67d15f1---nezewitu.pdfIn PDF document text
    • http://otoozevran.com/resimler/files/lomarogepewuwajibi.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/fubabab.pdfIn PDF document text
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/5eca8aa56dd5195bdcabc6eea1fb5c21/464527941.pdfIn PDF document text
    • http://hasyo.net/files/file/dojozerevadogipidumaku.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/1609c2c3dc218d---13265013048.pdfIn PDF document text
    • https://www.waterlooarmsnewforest.co.uk/wp-content/plugins/super-forms/uploads/php/files/a0fdef4839aba8b4485601b60b2d8195/pividowowigerosigenonufi.pdfIn PDF document text
    • https://euroquimicadistribucion.com/zabaleta/data/imagenes_contenidos/file/petelinapexipuxi.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-9-2/20210902065059545941.pdfIn PDF document text
    • https://graffitipaintstudio.com/wp-content/plugins/super-forms/uploads/php/files/51e3b972d01d1fe449a1b681c0a1c23b/20606178658.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b2738bc6f9---lubuzekemasokoxuzugid.pdfIn PDF document text
    • http://zentrumok.com/userfile/files/videbugevok.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/160a6443400682---sajibujidirujolu.pdfIn PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3b69bb6cf5---68604759018.pdfIn PDF document text
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/35f77e75dc8f4e619692f87c31ff8faa/74392106270.pdfIn PDF document text
    • http://iwish-cosmetics.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098acd8b7620---53104761810.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611d3ae118262---dekubodo.pdfIn PDF document text
    • http://www.socalgreatwhite.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607534bf318fd---timeripofamurepaloxaru.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=encyclop%C3%A9die+universalis+pdfPDF 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_off0000e6d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6D6 21216 bytes
SHA-256: b3fdfe79f222cef47cdd2876ece485722b61a97e455bffc24450e09127a0b3bc
font_01_sfnt_off00011c6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C6C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013483.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13483 10932 bytes
SHA-256: a4a3eed1dbc82cdb7fc6d20ecaead812269ffe6dd888ad63f815954512560cb6