Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b870b7bd5baed83…

MALICIOUS

PDF

86.8 KB Created: 2021-07-14 08:24:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9dffd216287d328eef137d3748ebfa0a SHA-1: c8a474f46dc6e69b1597b910f4f83c82240230f5 SHA-256: 4b870b7bd5baed83ce426bbf579c969972ee87204fa4331959cd0d9415a1b4ac
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites and are structured as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing or malware distribution sites. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with a phishing lure or a downloader for further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://aarogyamedico.com/userfiles/file/13463872283.pdf
    • http://vtaky.sk/media/file/besonejodepesuditozaja.pdf
    • http://bright-mineral.com/uploadfile/file/2021070200355993.pdf
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/824o3273rttetnfee0nh0p75d9/56064435100.pdf
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607164e36d2f4---nusazenewokepomo.pdf
    • https://mygamedaysports.com/wp-content/plugins/super-forms/uploads/php/files/556ee2b277e7de4c91a3a6642e749334/gegomabasigava.pdf
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/c02deaf19a5147d268a37794cfa1367a/33425501111.pdf
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b2265e5593f---fitesipifesomugaranave.pdf
    • http://quick-thailand.com/images/uploads/file/6460673127.pdf
    • https://georgiamusicpartners.org/wp-content/plugins/super-forms/uploads/php/files/b2d70e69cfce6a4428bc78517db08e55/65281353814.pdf
    • https://thejasmineway.net/wp-content/plugins/super-forms/uploads/php/files/8j61hc431ttakegbfg56dticsf/53821266702.pdf
    • http://ekolojikweb.net/upld/userfiles/file/65246983402.pdf
    • http://sanarina-coaching.de/ckfinder/userfiles/files/18512156913.pdf
    • http://nail-free.com/ckfinder/userfiles/files/16254394739.pdf
    • https://mytutr.com/wp-content/plugins/super-forms/uploads/php/files/b4af8cf9ce200fdfc11e2dbf30edb247/58821482656.pdf
    • https://plentis.eu/ckfinder/userfiles/files/vegojotujetilan.pdf
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608e92e60c720---mupadotuwujeraxa.pdf
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5025124ad---39466711670.pdf
    • http://historico.uts.edu.co/portal/app/ckfinder/userfiles/files/64819060985.pdf
    • https://ebooksweb.net/files/file/lovefolunulijuro.pdf
    • http://crosswaysrecruitment.com/userfiles/file/64171616192.pdf
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/lau6l65brinn04ak66uh8rioik/73295362135.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=structures+found+only+in+animal+cells
    • 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_off0000ef1c.bin
481bb3deb894a610cb404231062455a01cdcd74ffd814602559a3ad34f84862b
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF1C 10928 bytes
font_01_sfnt_off0001086c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1086C 16792 bytes
font_02_sfnt_off0001207e.bin
9707d6162fb589ed1cb45e689ae96ce9367a7da9888946a31d6be3fcb91ec158
pdf-font-stream PDF embedded font (sfnt) at offset 0x1207E 16848 bytes