Malicious PDF — malware analysis report

Static analysis result for SHA-256 8437f5f86d49d38f…

MALICIOUS

PDF

81.4 KB Created: 2021-06-27 02:07:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: dd4f24bdbdb7f2c40b8db477cc3745d3 SHA-1: 2039651b0a6daa5ed81ad185d7793b7b68c55aad SHA-256: 8437f5f86d49d38f967fe2b8510ef66e339980aa8f934c5f0a4de2b9edc84097
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many distinct hosts and URLs pointing to compromised CMS upload storage. The document body was unreadable, but the presence of numerous external links suggests the primary purpose is to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/4d5l8p8rbb265f18fbr3fc69kl/29759381651.pdf
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608169558e3a2---zivedepoziruwifole.pdf
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/84f62ef5f5bbd6c36838790308221191/sozedozo.pdf
    • http://nsdadventist.org/FCKData/file/24692981384.pdf
    • http://videofilm-tv.ru/content/File/liwuvakavetapafuwomufig.pdf
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/a1f1ced02902e938833a219c481cd872/sobumanuvejujerewanovoze.pdf
    • http://dedanskecasinoer.dk/userfiles/file/telekudakef.pdf
    • http://drive4smilesontario.com/clients/e/ed/ed023a0734c265ca673a92d1d81de675/File/derilave.pdf
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/84666306af9f1f627775a45095869808/91538775233.pdf
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c8b8c493702---98052815976.pdf
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8f3e0ccf4b---muvezodezunijagufake.pdf
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/i8en8uqtlqq3jshm167uakb936/48541843553.pdf
    • https://bmw-zona.ru/uploads/file/50449322898.pdf
    • http://ventilyatsia-v-sochi.ru/ckfinder/userfiles/files/29324648534.pdf
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b3a8783807b---xudejibujigesobepet.pdf
    • https://planet-for-events.de/userfiles/file/27796194701.pdf
    • http://sfera-vlad.ru/img/file/84445749344.pdf
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c133cd56879---zinifejivebesozujar.pdf
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/eaqvgbicdcvlaqmgncffg1et0j/tuzewibozojegiz.pdf
    • https://www.kalirich.com/wp-content/plugins/super-forms/uploads/php/files/88nir0afpnv7j76tfbtlp3d9q2/giduxetogujima.pdf
    • http://septumdent.com/img/userfiles/files/joxuv.pdf
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1606e447c01030---bulakigojutipezewid.pdf
    • http://www.apsetedavisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d0c3875473---396465183.pdf
    • http://mosjob.ru/images/file/puvipo.pdf
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/a9dd14490b7cd0343a76675629b26665/29311278576.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=let%27s+keep+dancing+on+the+broken+glass
    • 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_off0000d675.bin
ce572645bc44b381af58ee685936de1974befe725cf8f3ed664940d463aa2db3
pdf-font-stream PDF embedded font (sfnt) at offset 0xD675 18148 bytes
font_01_sfnt_off0001055a.bin
bb6a65716c19fc1a2f4e06f0ca490341d7c1a25c6a47da8ee9397acf3da29de9
pdf-font-stream PDF embedded font (sfnt) at offset 0x1055A 11016 bytes
font_02_sfnt_off00011e83.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E83 16792 bytes