Malicious PDF — malware analysis report

Static analysis result for SHA-256 66c44112916fbf94…

MALICIOUS

PDF

93.1 KB Created: 2021-07-03 11:19:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 4d609957ef52f4448b5665864f1b5732 SHA-1: 2c8f382374465926e30896d4a63324417c9f58b1 SHA-256: 66c44112916fbf94b90cf3bd4f4207ac1869c95f73ddf538f1fc294aacae8b0b
96 Risk Score

Malware Insights

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

The PDF file contains numerous external URIs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm for SEO manipulation or malicious redirection. The ML classifier strongly flags this PDF as malicious. No scripts were extracted, but the presence of multiple suspicious URLs suggests the document's primary purpose is to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 5

  • 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://yssnewlessons.org/UserFilesTwo/file/nuropadas.pdf In PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/sud0hjpplegba34m6i6i4cgn84/46166330669.pdfIn PDF document text
    • http://biosite.ru/images/news/file/bisevudipafulodepi.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/55bgus843h5go8mhjo1fq9e8j3/99682733604.pdfIn PDF document text
    • http://comicpapyrus.com/wp-content/plugins/super-forms/uploads/php/files/168be1b6763e4f539c32ed0fa20b58a9/13560769435.pdfIn PDF document text
    • http://sgyscom.com/upload_fck/file/2021-6-18/20210618223259513331.pdfIn PDF document text
    • http://shopexpert.com/app/webroot/files/userfiles/files/39729703775.pdfIn PDF document text
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/cc62db0bc89f000707abb3484ae06fff/lipugev.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/b96360b0191e2fe61b50a0dbf13da778/99407903364.pdfIn PDF document text
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f841850958---44312136672.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c66eea0dba8---56375552011.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160c949a2ee14c---jizigodiwifafoxare.pdfIn PDF document text
    • https://mama-light.net/business_school/uploads/file/41512637071.pdfIn PDF document text
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160bac74a70ddc---8903321260.pdfIn PDF document text
    • http://t-p-fortune.com/userfiles/file/dupofegubuzamil.pdfIn PDF document text
    • http://jyotiacademicpress.org/uploads/file/96706263783.pdfIn PDF document text
    • http://sllight.ru/design/img/upload/file/kaxomivo.pdfIn PDF document text
    • http://spoilersmensgolfclub.com/clients/865201/File/gogisefavoronivetakoguw.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/wixubixaj.pdfIn PDF document text
    • http://malbreil.com/userfiles/file/tedukaxananugilapeduf.pdfIn PDF document text
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/aaa82f69ea3ec2b9078b8884427e07dd/fenati.pdfIn PDF document text
    • https://www.axelendinggroup.com/wp-content/plugins/super-forms/uploads/php/files/2c6450bd5858781176054e2dee49aee3/jipodixumitonevukafone.pdfIn PDF document text
    • http://olsztyntransportmedyczny.pl/userfiles/file/voxodobeminilugenik.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=travel+photography+jobsPDF 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_off000107dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107DD 18372 bytes
SHA-256: 8817394c5ca0ac6770b631b68b187c95224bdb93895cf804525e15edacc771b1
font_01_sfnt_off000136ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136CE 10748 bytes
SHA-256: 419369a4138c3dc972011d6aa33fced277d48979702e1fb59a519a633fd3cbb0
font_02_sfnt_off00014f86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14F86 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1