Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf687bd85a76ec25…

MALICIOUS

PDF

86.3 KB Created: 2021-08-25 02:48:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: daff6993b29a2d932048376b759a776e SHA-1: e32ac4191354cd8b97e50a6ae26d9e9a8f16f3a1 SHA-256: cf687bd85a76ec250e0b8528f78e0f701ffea1e054bd046418f5745b05664b43
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised CMS upload directories and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://bleikss.com/userfiles/file/20350266849.pdf In PDF document text
    • https://onlinendttraining.net/files/66818070445.pdfIn PDF document text
    • https://tekdalyapi.com/upload/ckfinder/files/gevuvumafafarasomob.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b14f3edf617---potapukilufuzivepibal.pdfIn PDF document text
    • https://www.infrascale.com/wp-content/plugins/super-forms/uploads/php/files/f7bf13735262ae03383c033b322f011c/vezubetonabebaluzemewoxor.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6593f7b5dd---43600370570.pdfIn PDF document text
    • http://cokhihoaiduc.com/uploads/files/wetumovuro.pdfIn PDF document text
    • https://electrabicycles.pl/app/webroot/uploads/file/16212609743296.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1607ec699e6708---79784246957.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/160ad7b2557e0d---muxagu.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/160aaa3a857603---95444344002.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/16083bf094c697---kajorejapitelufofe.pdfIn PDF document text
    • https://indacphuc.com/wp-content/plugins/super-forms/uploads/php/files/sdplatvavcih5de33uiprc3hc5/gujeraw.pdfIn PDF document text
    • https://laser-arena.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1607002de16f29---namarokipobi.pdfIn PDF document text
    • http://www.maderas-navarro.com/ckfinder/userfiles/files/vitowetubalupulizuzafigo.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f919cd8b65c---fatip.pdfIn PDF document text
    • https://aquatrustfina.com/userfiles/file/liviwane.pdfIn PDF document text
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16081439ebe1b7---tuzevovipe.pdfIn PDF document text
    • http://china-zub.ru/userfiles/file/46263934328.pdfIn PDF document text
    • https://fobiy.net/wp-content/plugins/super-forms/uploads/php/files/d9b159de4222b608fafecbdfe3d3d91b/fegilo.pdfIn PDF document text
    • http://tulsamemorialclass1969.com/clients/8/8b/8b8b36ecbaf17f244e47af75a29dfbe2/File/46127221257.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0cead60dfb---tekewopaw.pdfIn PDF document text
    • https://www.southdownscellars.co.uk/ckfinder/userfiles/files/matizenediper.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080443cacb81---fevibowexexutogel.pdfIn PDF document text
    • http://tochalco.com/uploads/files/49911306794.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=what+light+do+orchids+likePDF 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_off0000eca1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECA1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000104b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104B8 10632 bytes
SHA-256: 93565974b03881dd57fd90121ccba4c7c22f3ac66b20b15802739d4b1f426a2a
font_02_sfnt_off00011cfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CFE 17356 bytes
SHA-256: ae12ecc80ad72bc98e576410cd2bf5f9eeb9cbf678dfd0c290ef9901c380ca86