Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb71acb91cd0da14…

MALICIOUS

PDF

83.6 KB Created: 2021-07-16 10:30:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 617e27c73480501e742a515edfc5d715 SHA-1: 28e2badb4b6b1a855f3d577b8ec4951c5860bf40 SHA-256: fb71acb91cd0da14f62ac7d24c362356bf9c0b4e0f75f24450af8cb2b5f00051
156 Risk Score

Malware Insights

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

The sample is a PDF that contains numerous links to external resources, many of which are hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically identified as phishing or trojan activity. The embedded URLs suggest a link farm designed to redirect users to malicious content, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ecade8df1b---6531500973.pdf
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/16087c2a1c1757---varuvuk.pdf
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609b0d02787b5---wanizetiganikabajora.pdf
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160c25817940c2---43931566155.pdf
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160806a489b1ca---fudixapolizobifinifakuj.pdf
    • https://accesoriosalmayor.com/images/userfiles/file/bekedibuli.pdf
    • http://sy-smile.com/upload/files/fenebimefoxev.pdf
    • http://lncxjzxxw.com/upload_fck/file/2021-5-15/20210515161710218408.pdf
    • http://urgentcarepb.net/userfiles/file/kazeluraxir.pdf
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a94dc4dad7b---20056938160.pdf
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e4e9450650e---furanovi.pdf
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160e00a28e96f4---56363841007.pdf
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c9337a2541a---89084815975.pdf
    • http://comp-art.ru/userfiles/file/xibojumesubitatibudijud.pdf
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/160be2c37d4dec---piguvuwiwe.pdf
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/1b88isdmelm9k4ndfnra95svfq/kuwezukifalawinuj.pdf
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/47273709429c724de4e925dcf93c6847/73504990663.pdf
    • http://wannawwannie.pl/userfiles/file/zexowuxofaferut.pdf
    • http://centralgiving.com/media/userfiles/file/28655217018.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=how+to+disable+windows+auto+update+windows+10
    • 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_off0000e2a6.bin
86a94a7f6ed56f1c11005d43bfb8dc69019f2fb42d592c649e009f362998afa7
pdf-font-stream PDF embedded font (sfnt) at offset 0xE2A6 17564 bytes
font_01_sfnt_off0001106e.bin
d7c2adf180c2e71e336c8c7b4293524cefd8ecf71204f1ab0d04188a3caf1b0f
pdf-font-stream PDF embedded font (sfnt) at offset 0x1106E 10776 bytes
font_02_sfnt_off0001292b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1292B 16792 bytes