Malicious PDF — malware analysis report

Static analysis result for SHA-256 b66dfc504b4d69b3…

MALICIOUS

PDF

71.0 KB Created: 2021-09-08 11:22:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: b8ca3d3995e0982c6c1c7392625442c8 SHA-1: e525255d03750a6cf27ff77d655ef1ced7d104db SHA-256: b66dfc504b4d69b302c883c5631e781ada4a86f8ec36178be097d190684ba768
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress upload directories and disposable hosting sites. These links are likely used to distribute further malware or conduct phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160bf458b6ff52---63535327882.pdf In PDF document text
    • http://iwish-cosmetics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c43c014b9b---rugotosuravalebuk.pdfIn PDF document text
    • https://pasarangroup1.com/contents//files/gewepubafowitedirabuf.pdfIn PDF document text
    • https://linhngapt.vn/upload/files/liwegiminokasato.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160c2921de7a9f---juxemupu.pdfIn PDF document text
    • http://archinfo.ru/uploads/file/29101509356.pdfIn PDF document text
    • https://foreningenflex.se/anvandarbilder/173/files/38233957265.pdfIn PDF document text
    • https://ducthai.vn/userfiles/file/soleninozazirivumejaf.pdfIn PDF document text
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/160bb0dc2ee4a4---19592960456.pdfIn PDF document text
    • https://hotelindigha.com/FCKeditor/file/gopajabodebepuviwowumowa.pdfIn PDF document text
    • http://f-okinawa.com/img/tmp/files/kowuwikulixetusa.pdfIn PDF document text
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160bd9e5a5f453---72134213678.pdfIn PDF document text
    • http://exclusivelimoservice.com/ckfinder/userfiles/files/82854688576.pdfIn PDF document text
    • http://cdkkck.com/uploadfile/file/20210821105958.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/5e0d7b6a348f029a4c3328d8e46e42fb/besumewopuwokifudajafeto.pdfIn PDF document text
    • http://teranor.com/ckfinder/userfiles/files/74734847505.pdfIn PDF document text
    • http://marsalanoleggio.it/userfiles/files/jiwibilofewasev.pdfIn PDF document text
    • https://simon-daulte.com/ckfinder/userfiles/files/pawutawafagivazebafasem.pdfIn PDF document text
    • http://scpt.it/userfiles/files/temufenijizodebodix.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/788a747a131dd7a064e3c3c68c8dba74/50045205401.pdfIn PDF document text
    • https://ienter.bg/files/27407265433.pdfIn PDF document text
    • https://pinotcar.com/wp-content/plugins/super-forms/uploads/php/files/f17a3f765cb66e385ae1458f851d0682/15488565805.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607235d754ebb---15822393528.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=inductive+approach+in+research+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_off0000b6c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6C4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cedb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEDB 10788 bytes
SHA-256: e612d9d9adc6410a6f4e6b0b9e12f31bb47841b047bf7650679d030f8e6ea464
font_02_sfnt_off0000e7aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7AA 15380 bytes
SHA-256: abc1b38d9e4d78064ce77e74ce84dfbedeb91d5b241ce507e1141a67a7ed782b