Malicious PDF — malware analysis report

Static analysis result for SHA-256 5248e6bfebc3581f…

MALICIOUS

PDF

76.8 KB Created: 2021-09-20 14:32:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a6b3eb34c57536353ea41e296601469a SHA-1: 8b78b5a0fdb6d92f2e13d0d32f941d71914a0a82 SHA-256: 5248e6bfebc3581fef7e331e6c010c4e4db6322b20030e5bb3b4dab8ddb14599
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm. It contains multiple embedded URLs pointing to various domains, suggesting an attempt to redirect users to potentially malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links, further supporting a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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 https://inwebjor.ru/uplcv?utm_term=the+art+of+statistics+david+spiegelhalter+pdf PDF link annotation
    • http://tgroupsrl.com/userfiles/files/fawuxozemojamusorewa.pdfIn PDF document text
    • https://bharatceramics.in/ckfinder/userfiles/files/tobigo.pdfIn PDF document text
    • https://amgaa.org/temp/files/39998719532.pdfIn PDF document text
    • http://ckud.handysociality.com/upload/files/bafepelezeta.pdfIn PDF document text
    • http://metafelix.it/userfiles/files/xonibu.pdfIn PDF document text
    • https://oxi-dental.ro/imagini_ws/63446229879.pdfIn PDF document text
    • https://labelmarket.eu/data/file/15782250086.pdfIn PDF document text
    • https://bazk.info/public_htmluploads/file/48900897731.pdfIn PDF document text
    • https://divinenine.net/userfiles/file/46177336003.pdfIn PDF document text
    • http://starinviter.com/ckimagefiles/55451314994.pdfIn PDF document text
    • http://poptheme.cn/uploadfile/files/20210908_140218.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/562a7332ae3b6237217629f573181368/vixezedodiximotuwixakuvo.pdfIn PDF document text
    • https://nls.vn/upload/files/29827057742.pdfIn PDF document text
    • http://seyrimerdin.com/userfiles/file/82700554353.pdfIn PDF document text
    • http://tsnpharma.com/upload/files/23045116508.pdfIn PDF document text
    • http://chikatere.com/Upload/files/36420872285.pdfIn PDF document text
    • http://www.psychophonie-tarbes.com/ckfinder/userfiles/files/daxuvurujisak.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/161402e379f353---5906837967.pdfIn PDF document text
    • https://solidpractise.com/files/userfiles/file/vopukabozugotuwiwakovoli.pdfIn PDF document text
    • http://futuralagoparking.eu/userfiles/files/wowivobadodubibopuligib.pdfIn PDF document text
    • http://kammerchor-lindau.com/file/tagowokujofuzedo.pdfIn PDF document text
    • https://praktijk-fix.nl/userfiles/image/file/88897295495.pdfIn PDF document text
    • http://stonestudio.pl/files/upload/file/7761662387.pdfIn PDF document text
    • http://visusmarble.com/images_upload/files/debetotavava.pdfIn PDF document text
    • http://celyroknaterase.sk/editor_uploads/system/files/52841413987.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ad7f3e5fac---2673204626.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_off0000c9ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9ED 10824 bytes
SHA-256: 81901e2eac2b61a7794848881e021c9cf37b0f83e8ef790d14505e628b51da94
font_01_sfnt_off0000e2e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2E3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000faf5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAF5 16484 bytes
SHA-256: d71dcd9b8f65a137416996a3772154a7755b7707d86a11374fca59cdea72c29d