Malicious PDF — malware analysis report

Static analysis result for SHA-256 31d4d03a8329936f…

MALICIOUS

PDF

74.7 KB Created: 2021-08-28 08:38:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3f1223f5ff5a974be0190f59285e1837 SHA-1: ba6e3321a8c75105a29691b4a337b1296e0a8fcf SHA-256: 31d4d03a8329936f11adc0e138fc6a0bf0ed074a99817f6b3849726846c3f8c0
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites and disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://petala.gr/userfiles/file/wodowoka.pdf
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16087dda97cb74---35819363225.pdf
    • https://willes-gb.com/uploads/files/202108140431569262.pdf
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e330863936---merakupajubosixuga.pdf
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/6bff3tgjadk02ln17vhc9fs8ln/javegurab.pdf
    • https://him-home.ru/wp-content/plugins/super-forms/uploads/php/files/2b304d508b49b042586db778acc58f47/lobomidivetozuvidum.pdf
    • https://comtraining.cl/userfiles/files/224977062.pdf
    • http://maidnheaven.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1dadc59659---43461833696.pdf
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16102d4b7f33eb---pimekitasolakexoliso.pdf
    • http://ya-ke.cn/admin/upload/wikunuwewibumiliwitora.pdf
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/160987c68189bb---jotogevowi.pdf
    • http://ithalattagarantibelgesi.com/resimlerfiles/70677032283.pdf
    • https://ikincielinmak.com/upload/ckfinder/files/jukobidalokizudu.pdf
    • https://cwlighting.com/wp-content/plugins/super-forms/uploads/php/files/8882b162e759beb550b8e7030ae02f0c/29819196256.pdf
    • http://imhome-listings.com/userfiles/files/kagegopobatun.pdf
    • http://yachtandgulet.com/userfiles/file/7444192613.pdf
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160b9faceeb362---nasudolaxotubi.pdf
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/8mmcrank2qaaqou9m0k9derb37/vifaxaramovotofaz.pdf
    • http://gardens-spa.com/user_pict/file/purinijosamoguxa.pdf
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089da705fc56---vutib.pdf
    • http://meetburgerusa.com/uploads/files/18988913876.pdf
    • http://statsale.com/data/upload/ck/files/dawuxuw.pdf
    • https://www.synergyheart2heart.team/wp-content/plugins/super-forms/uploads/php/files/acml2j30b4qsi14c7rh04l8bc3/32519477975.pdf
    • https://horgaszvelem.hu/ckfinder/userfiles/files/52981075325.pdf
    • http://tataservice.it/userfiles/file/86120991726.pdf
    • http://connect-senior.ch/uploades/userfiles/file/razuwotelorodujibukigozo.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=software+tools+in+pascal+pdf
    • 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_off0000c2ba.bin
b891ec2047c8447a2ca0506a39c35d7536783f25dfbe6e85c2e7e9aff1e35112
pdf-font-stream PDF embedded font (sfnt) at offset 0xC2BA 16396 bytes
font_01_sfnt_off0000ec1c.bin
897553e8ce5cda8f4495af3537b7f2f87fee26e7e733601c0cff327ba051761f
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC1C 10772 bytes
font_02_sfnt_off0001050d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1050D 16792 bytes