Malicious PDF — malware analysis report

Static analysis result for SHA-256 99ad838400023e75…

MALICIOUS

PDF

107.8 KB Created: 2021-07-02 10:07:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6e9e7d9cbcac34323ef09e807ee700b4 SHA-1: 70ae499c07c732ba5bc17c66d3e9525f7c9b388b SHA-256: 99ad838400023e75283b090010975cf5043594ed7b007769394b54d76c569d98
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised or disposable domains, indicating a link farm designed to direct users to malicious content. ClamAV and ML classifiers strongly indicate malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL patterns suggest exploitation of PDF vulnerabilities or social engineering to lead users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

Heuristics 6

  • 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.
  • 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://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a78b603f741---93667717934.pdf
    • http://otelm4b.ru/admin/ckfinder/userfiles/files/jiresinidanobusovuzu.pdf
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/f2a407aa44d620d8e63a18017210e89b/44695235931.pdf
    • https://spaslask.pl/wp-content/plugins/super-forms/uploads/php/files/gtb4embffd202spn0qmbpbql17/nuzumatemerozovoga.pdf
    • http://cukiernia-waltar.pl/qcms/userfiles/file/jamadi.pdf
    • http://purifoy2020.com/clients/1/11/118d8b7ee1ea4bab8fb19da95c56260f/File/50405908008.pdf
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/16087a19962f74---34721539539.pdf
    • https://nailseasupportgroup.com/wp-content/plugins/super-forms/uploads/php/files/1d054168d86094846ea52a2343c7cb88/59516921862.pdf
    • http://tjsijiqing.com/ckfinder/userfiles/files/2021/0624/b9a12bbb3bc978159c84947e4214351f.pdf
    • http://fittbike.hu/files/file/punazosukixukutux.pdf
    • http://impex-italia.it/userfiles/files/83692010770.pdf
    • http://k1a.ru/images/files/file/kopiveperelow.pdf
    • http://geyikkimya.com/userfiles/upload/file/24697042399.pdf
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/13df8162e02e51137bef0db269dbb645/77626643933.pdf
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/160ce54b185921---23762143390.pdf
    • http://cabinet-blin.fr/ressource/site-image/files/61406978686.pdf
    • http://allaboutdowney.com/userimages/zugub.pdf
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070293200d1e---9140815434.pdf
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/42915c9d4a056e304f8efb1fff421612/80459110031.pdf
    • https://campermagazine.tv/public/file/nipejozek.pdf
    • https://belgradenightlife.info/wp-content/plugins/super-forms/uploads/php/files/ahf8j5nv680k2uih6g98m7i4q5/rarapakemetib.pdf
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1609968a4b818c---nowanaxotubowud.pdf
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/vghlshvs542bv1eals3kfu0fm4/rejisakewerebenimatazowow.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=nonbinary+meaning+sexuality
    • 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_off00014200.bin
7d29065264d8232898e273c4b7052dc6ae7407d8ba668adc4ecf0cfe5c392711
pdf-font-stream PDF embedded font (sfnt) at offset 0x14200 10884 bytes
font_01_sfnt_off00015b39.bin
5ac7e690f2618486e2d5c0803bec2cdf16c275c093a0d82726d19dfd1369c492
pdf-font-stream PDF embedded font (sfnt) at offset 0x15B39 18236 bytes
font_02_sfnt_off00018ad6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x18AD6 16792 bytes