Malicious PDF — malware analysis report

Static analysis result for SHA-256 2451b494b757e3fc…

MALICIOUS

PDF

81.4 KB Created: 2021-08-14 23:42:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: bb50c349f87a6219de291faa4f80af22 SHA-1: db6375af0e4b98e124ada86323254f610cff3118 SHA-256: 2451b494b757e3fc59afe0fcb02a746db5113adfb1597efea7909e5bf3a88378
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, with numerous URLs pointing to compromised CMS uploads and disposable hosting, likely to redirect users to malicious sites. The presence of external URIs and link farm heuristics strongly suggests an attempt to lure users to external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://lex-ter.ru/admin/ckfinder/userfiles/files/3697247493.pdf In PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc256ec2da---talekumoxedekavumekazuja.pdfIn PDF document text
    • https://textosolutionslinguistiques.ca/upload/editor/file/86592014487.pdfIn PDF document text
    • http://www.oomedia.com.tw/ckfinder/userfiles/files/dowavoxetirusosojewur.pdfIn PDF document text
    • http://gptools.net/userfiles/file/6299289395.pdfIn PDF document text
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/d6e0afad194e58a167966beebd2b7dd3/45446664625.pdfIn PDF document text
    • http://bluedevils59.com/clients/862365/File/18470873102.pdfIn PDF document text
    • http://alarcon-v.com/editor_upload_image/file/tiwowijawurater.pdfIn PDF document text
    • http://pr-jam.com/ckfinder/userfiles/files/totawuwiveza.pdfIn PDF document text
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/089dcf638bc58f73287754a4c288ae8b/68410993618.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/160a216f9a96b0---58154515514.pdfIn PDF document text
    • https://jotelek.hu/files/file/samene.pdfIn PDF document text
    • https://resulgame.com/calisma2/files/uploads/geledefuxu.pdfIn PDF document text
    • https://www.straightmyteeth.eu/wp-content/plugins/super-forms/uploads/php/files/fb9e1696690ca8b5d9b0e4a39bed1a2f/58354254264.pdfIn PDF document text
    • https://strategieb2b.com/userfiles/file/fobilazugobisa.pdfIn PDF document text
    • http://sea-cruise.ru/ckfinder/userfiles/files/gudelopagovofen.pdfIn PDF document text
    • http://bamt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1607b51c3be53a---zinosuvijupedasasogew.pdfIn PDF document text
    • http://hnht-electromagnet.com/d/files/76180648256.pdfIn PDF document text
    • https://responsible-tourism-alliance.com/content_file/files/46419516862.pdfIn PDF document text
    • http://patrick-vallot.com/upload/files/xalenaguwe.pdfIn PDF document text
    • http://abwmountvernon.com/uploads/files/bipemu.pdfIn PDF document text
    • http://fixafilm.se/userfiles/file/23746935553.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=cell+growth+and+division+test+answer+keyPDF 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_off0000d878.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD878 17548 bytes
SHA-256: 30342d6458871e28765b9facd89d8fa9f46e6d5b41df60a853ebefe1356fd574
font_01_sfnt_off0001067c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1067C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E93 10916 bytes
SHA-256: 8b3a294f0b29ac79141c6272b55c262d83d5f6bdf99de54f1e51611372eafc4d