Malicious PDF — malware analysis report

Static analysis result for SHA-256 51e73c8a7e0d7ce6…

MALICIOUS

PDF

77.4 KB Created: 2021-09-16 10:00:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0bbd2469cd73ddd7188e464e2c0c8755 SHA-1: 33b1bea7d81df6da1bae4cdaa89a37bef35043d6 SHA-256: 51e73c8a7e0d7ce6e87edc3913f2aec0e5216d49b5c3a11740e5633086f3b954
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous links to external websites, many hosted on potentially compromised or disposable domains, suggesting a link farm or phishing lure. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards techniques commonly used for distributing malicious content or redirecting users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://pactolous.hu/upload/file/93193346102.pdf
    • http://www.golfusa.be/userfiles/files/72738114466.pdf
    • http://eg-connect.com/php_codes/Scott/VieauAssociates/code/userfiles/file/49172335691.pdf
    • https://ohcsi.com/ckfinder/userfiles/files/gamarakaxetifoxe.pdf
    • http://drukarnia-skawina.pl/app/webroot/media/files/46905807320.pdf
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/bdef912677d9361d4c707c5a46bb2325/viwasar.pdf
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/161425ca920885---kenotudos.pdf
    • http://juentai.com/userfiles/files/69110887108.pdf
    • http://rigdrilling.org/userfiles/file/17954929433.pdf
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/76caf202bf9a3a2550fb705d2e5f8175/55748871737.pdf
    • https://degardo.hollandpazsit.hu/ckfinder/userfiles/files/buvilotix.pdf
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/cmvq0na7tllguc1obugbpr7080/karelesabaraniperunuj.pdf
    • http://nprofit.hk/userfiles/99445311470.pdf
    • http://minhquoc.vn/ckfinder/userfiles/files/werabixipitakatoz.pdf
    • https://momentous-inst.com/uploads/image/files/60586814895.pdf
    • http://ahxxzx.com/userfiles/202109/file/25938901528.pdf
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/1614047515388a---rofowijibivikeru.pdf
    • http://f1-rennsimulatoren.de/userfiles/file/sowawakotalexipuvavi.pdf
    • http://dainichiji.com/upload_ckr/files/worovexamaxuvipevilagar.pdf
    • http://agataklimowska.pl/userfiles/file/nisonerifariduk.pdf
    • https://hogozaty.com/ckfinder/userfiles/files/30963095482.pdf
    • https://machnik.net/ckfinder/userfiles/files/diwagar.pdf
    • http://www.pacautomarketing.com/file/20979003064.pdf
    • https://thibiditrading.com/public/userupload/files/49595650811.pdf
    • http://fastcredit.ge/userfiles/file/26382243418.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=crop+pdf+page+online
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cb38.bin
0c8fd143878b40611ae957349a5f284a2c7040709e885444b18decf1ef725f7d
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB38 10440 bytes
font_01_sfnt_off0000e2b6.bin
cdfd396312a748967530569739ec567832416da337b3c8a3bbeb2e13d205338d
pdf-font-stream PDF embedded font (sfnt) at offset 0xE2B6 17436 bytes
font_02_sfnt_off00010f9c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F9C 16792 bytes