Malicious PDF — malware analysis report

Static analysis result for SHA-256 fd843bee90e88e9b…

MALICIOUS

PDF

80.4 KB Created: 2021-09-16 13:38:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8c99341cc970e04edc43e1477bcfece7 SHA-1: 31cd7a70d57b5f1ab1d74cc082a9cea8449cf4c0 SHA-256: fd843bee90e88e9be0ed8e7eabeb63bca00a6c3a39670b65d20b672cd9cd8e6e
164 Risk Score

Malware Insights

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

The file was detected by ClamAV as a phishing trojan and flagged by an ML classifier. It contains embedded JavaScript and numerous external URIs, including links to compromised CMS uploads and disposable hosting, suggesting it is used to redirect users to malicious sites. The presence of JavaScript indicates an attempt to exploit vulnerabilities or execute further malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://nomylo.ru/uplcv?utm_term=geronimo+stilton+ebook+free+download
    • http://luxlustry.ru/img/upload/dokezi.pdf
    • https://hagakure.by/upload/editor/files/71163552911.pdf
    • https://postelezmasivu-ostrava.cz/ckfinder/userfiles/files/93806641045.pdf
    • http://longruiglass.com/ckfinder/userfiles/files/20210914_184341.pdf
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/161339aff4a7db---2366548525.pdf
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/16133e62867cb9---numusule.pdf
    • http://print-printonline.com/ckfinder/userfiles/files/lotelukoz.pdf
    • http://csc0351.com/userfiles/file/20210904235100_cxbnc6.pdf
    • http://hitecds.com/userfiles/file/jafiroxumanite.pdf
    • http://studio70.eu/userfiles/files/49853425197.pdf
    • http://chelseafoodmart.com/uploads/files/76486957156.pdf
    • http://braciszewska-klimek.pl/fck_files/file/falikuwobolilolas.pdf
    • http://aldo-ins.com/userfiles/file/11357137155.pdf
    • http://griesvoegwerken.nl/UserFiles/file/tobimokugevutolarena.pdf
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/161407436b452a---verokofuvuwazumobediz.pdf
    • https://vannordenvastgoed.nl/userfiles/file/retunagatuxi.pdf
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161397def1551d---89819214617.pdf
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f6d57bca87---28258676280.pdf
    • http://cleversystems.ru/userfiles/file/kupexejasezuvajukoxal.pdf
    • http://tw-tms.com/uploadpic/xw/files/nivobujujatanosug.pdf
    • http://carscaso.com/js/upload/files/nuvufukawupojevawifed.pdf
    • http://prunay-en-yvelines.fr/ckfinder/userfiles/files/lixixututono.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_off0000d515.bin
dd333b754739674162d9b7c526e111858090e43346df8a79f28bdf493441f399
pdf-font-stream PDF embedded font (sfnt) at offset 0xD515 17148 bytes
font_01_sfnt_off00010233.bin
880e7afaeea02c79580e9e8f7b5c9cbd625b434b343453680c5f881b38f08862
pdf-font-stream PDF embedded font (sfnt) at offset 0x10233 10872 bytes
font_02_sfnt_off00011b69.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B69 16792 bytes