Malicious PDF — malware analysis report

Static analysis result for SHA-256 f90b9bd05d9f37e6…

MALICIOUS

PDF

85.8 KB Created: 2021-07-15 17:58:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 3f8b029f769c8a78583d0566542cfbf3 SHA-1: 93437593a5d2edc981cd3aa6cca4222294b8d78c SHA-256: f90b9bd05d9f37e6663957de227f824adb01cff2a6db30897c165952b4532a6f
126 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many pointing to compromised WordPress upload directories, indicating it functions as a link farm. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports a malicious intent, likely to redirect users to phishing sites or download further malware. No scripts were extracted, but the structure suggests a malicious document designed for initial access via phishing.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.3396

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://ka-base.no/images_content/file/muxapuxufukuxapa.pdf In PDF document text
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/9ea468280d6432e8baf6bd2a9d204970/83957742356.pdfIn PDF document text
    • https://www.rydalmereprestige.com.au/wp-content/plugins/super-forms/uploads/php/files/5gfukfsr6dbd5glsn4egv7nmss/gedisabujaxifezuripexa.pdfIn PDF document text
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/0e77e102d83025152b351b6cb57c6fd1/98212790850.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c11ea24ccb5---4041932352.pdfIn PDF document text
    • https://canadianrelocation.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607ce4360d12f---fezatatelutajojixedotiji.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/kazukifepufi.pdfIn PDF document text
    • http://phamtrangia.com/upload/files/88144823280.pdfIn PDF document text
    • http://agapetown.net/ckfinder/userfiles/files/611394324.pdfIn PDF document text
    • http://marketypik.pl/zdjecia/fck/file/74356054613.pdfIn PDF document text
    • http://kubak-ubezpieczenia.pl/userfiles/file/1035705355.pdfIn PDF document text
    • http://gojjang.com/uploads/files/42494101826.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16071241bca7b7---75366648038.pdfIn PDF document text
    • http://jedwines.com/cmsCart//upload/file/fozejawubigokesudisu.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b197b87dcbe---44153443539.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c559e904217---padaxira.pdfIn PDF document text
    • http://df-2.de/images/daten/file/69596271853.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/a28d753e9ccd558f8bb9cedf5f3b6c11/7155806390.pdfIn PDF document text
    • http://thegioituigiay.net/uploads/files/giluvamemosamijopusojiraf.pdfIn PDF document text
    • http://nhs1980alumni.com/clients/878257/File/81375093149.pdfIn PDF document text
    • http://aiken7050.com/clients/5/51/510ae66c864a6d23552e02d1b5190e2c/File/mujosozelabi.pdfIn PDF document text
    • http://cheumst.com/upload/fckeditor/file/27962641835.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=top+songs+without+wordsPDF link annotation
    • 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_off0000fc21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC21 10480 bytes
SHA-256: 1a5380647295345f766156df9b9082bc952c00fd38f3cad6fa9f722d96852c16
font_01_sfnt_off000113c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113C1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012bd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BD3 16764 bytes
SHA-256: 635fed34fbf11c4ca3934b72bf3ac3a7e9988369df019ced75cf8b5680384139