Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6438d08f4e0f98c…

MALICIOUS

PDF

68.1 KB Created: 2021-09-21 13:56:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: eba7fd7bb08d14154b04a42db84066dd SHA-1: e704b070ad5e87a213a1789d89b1b7bb2eb62703 SHA-256: a6438d08f4e0f98c6073abda0afb9a34d95172f8546d0733633fec4abd3c3d53
184 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript and numerous URLs, many of which point to compromised websites or link farms. The presence of embedded JavaScript suggests it may be used to exploit vulnerabilities or redirect the user to malicious sites, aligning with T1059.007. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest the document's purpose is to host or link to malicious content, likely as part of a phishing or SEO manipulation scheme. The 'SE_CALLBACK_LURE' heuristic also indicates a potential for social engineering tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

Heuristics 8

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://hkbca.org/UploadFiles/file/20210906235249105.pdf
    • http://multiseal.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/16135b3518def9---pulavitowef.pdf
    • https://www.bramfordgc.co.uk/ckfinder/userfiles/files/xafivor.pdf
    • http://synagoge-stommeln.de/ckfinder/userfiles/files/96469204580.pdf
    • https://la-klamm.org/Files/files/lukapulovaziwovexaxatosa.pdf
    • http://hokkaido-love87.com/app/webroot/js/ckfinder/userfiles/files/98119929040.pdf
    • http://full814.com/upload/files/lowisoviwu.pdf
    • http://lynhuagiasi.com/Images_upload/files/kibebejaxo.pdf
    • http://gizmakina.com/depo/sayfaresim/file/87637788268.pdf
    • https://qian-ho.com/upfiles/editor/files/wexasigux.pdf
    • http://chemicalengineers.ie/images/juzogefoxizuxi.pdf
    • http://massimobertoarchitetto.com/userfiles/files/kisitebobobukenil.pdf
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161404380c8f3d---futum.pdf
    • http://ayrh.internet-match.com/upload/files/60075312912.pdf
    • https://studiecarriere.it/uploads/file/78518742291.pdf
    • http://csp.hu/editor_up/31451686455.pdf
    • http://faurerom.com/userfiles/file/84973562210.pdf
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/alv16vfr01l46o28ddmbrg2vu0/2277941558.pdf
    • http://erpos.sk/data/files/bikodepilizuxavepuxena.pdf
    • http://findingthegrey.com/userfiles/file/xotiwabopuw.pdf
    • https://a-guskov.ru/uploads/files/23242560432.pdf
    • http://f-okinawa.com/img/tmp/file/42240608239.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=programas+para+ver+tv+en+android
    • 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_off0000acc7.bin
c02cb4ac7cff96929e6cf3f43064a2090a416bb57d34eeaf7c4053be2fc09134
pdf-font-stream PDF embedded font (sfnt) at offset 0xACC7 15296 bytes
font_01_sfnt_off0000d253.bin
5de06d5d9782e019ab5c3e911acc7a8a44923014c163c2c958eaddd556d77927
pdf-font-stream PDF embedded font (sfnt) at offset 0xD253 10756 bytes
font_02_sfnt_off0000eae5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEAE5 16792 bytes