Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec4de9a027d51d07…

MALICIOUS

PDF

80.8 KB Created: 2021-09-16 08:05:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 6b58048dcbc3cac2ea692f8001310b40 SHA-1: 5ca84e705ee31a0609c51557cae31eed30608b34 SHA-256: ec4de9a027d51d0716e6dde190e35d30af840731f7c1734672d01494123b9fb4
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress sites utilizing form builder plugins for file uploads. The ML classifier strongly indicated maliciousness, and the structure suggests a link farm designed to redirect users to potentially malicious content or phishing sites. No scripts were extracted, and the document body was unreadable, but the URL patterns and heuristic firings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://oniceh.ru/uplcv?utm_term=karaoke+songs+app+offline PDF link annotation
    • http://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613286ec045da---38929447036.pdfIn PDF document text
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613adea45f6de---turobugutufivozulejatudi.pdfIn PDF document text
    • https://psg66.ru/admin/ckfinder/userfiles/files/belegakixew.pdfIn PDF document text
    • https://www.jancsoalapitvany.hu/ckfinder/userfiles/files/xadinefebaruvimokununexuj.pdfIn PDF document text
    • http://ellenia3.eu/userfiles/files/jakujef.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161353c19d1559---41659942932.pdfIn PDF document text
    • http://ontis.sk/editor_uploads/system/files/10943217567.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab9262447b---noxovilexixusawegokomi.pdfIn PDF document text
    • http://kargo-box.com/uploads/files/mufaxip.pdfIn PDF document text
    • http://chiangmai-esc.net/user_img/files/xewokalafedomis.pdfIn PDF document text
    • http://abogadosaguilar.com/ckfinder/userfiles/files/97537482558.pdfIn PDF document text
    • http://househouse.it/userfiles/files/mujomimumebeleseganew.pdfIn PDF document text
    • http://women-for-marriage.com/ckfinder/userfiles/files/51639897719.pdfIn PDF document text
    • http://dr-onesrl.com/userfiles/files/pupuje.pdfIn PDF document text
    • https://sarenpinler.com/calisma2/files/uploads/64399028581.pdfIn PDF document text
    • https://briljant-maleri.se/UserFiles/files/vodarusuvelumotumipotev.pdfIn PDF document text
    • http://aallergy.friend-match.com/upload/files/52797902482.pdfIn PDF document text
    • http://flomojapan.com/upload/files/gamukukikem.pdfIn PDF document text
    • http://hoya-system.com/uploads/files/202109101245114212.pdfIn PDF document text
    • https://dzido.pl/userfiles/file/10464223020.pdfIn PDF document text
    • https://floridainvestment.cz/files/file/83776978865.pdfIn PDF document text
    • https://carcable-bg.com/uploads/pictures/files/fuvuvosijozu.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_off0000d7d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7D1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000efe3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFE3 17724 bytes
SHA-256: feb11de353b5550597835ad6985013b3713ce0fd562f6e33f5b31a98b5882082
font_02_sfnt_off00011dd7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DD7 10516 bytes
SHA-256: b63da6cd82fd9c4916d3db161d9201e998b294104003e243119416ba6f6c5a3b