Malicious PDF — malware analysis report

Static analysis result for SHA-256 771b53bb2b1ec828…

MALICIOUS

PDF

352.5 KB Created: 2021-07-23 17:58:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 99b62212e8bc5a8341fc705b120d568b SHA-1: 2813ae51a8758ef76952b3fa29bfb30dbd601034 SHA-256: 771b53bb2b1ec8283db129e5078cca6e1d5e08283bd44476d8a44f1b26496ec6
126 Risk Score

Malware Insights

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

The sample was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous links, many of which point to compromised WordPress upload directories, suggesting an attempt to host and distribute malicious files. The document body is heavily obfuscated and unreadable, providing no direct clues to its intent beyond the presence of these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8489

Heuristics 5

  • 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.
  • 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 http://martom24.pl/martom/userfiles/file/38294621358.pdf In PDF document text
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e537eb49f02---87954935339.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/e84fe35960392d82ef14785e5ab5b117/17339484079.pdfIn PDF document text
    • http://ozgu-yapi.com/firma/files/50427732389.pdfIn PDF document text
    • http://originalcheck.it/public/img_admin/file///dokuwiterewuwozanigagovo.pdfIn PDF document text
    • https://evg-prague.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16091f9f4e09b1---41009338819.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b9c9296152---jaxonakokawigipadovibuxen.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082d42aaaca1---lubofas.pdfIn PDF document text
    • https://zahnersatz.pl/userfiles/files/16171597826.pdfIn PDF document text
    • http://www.publicitymailing.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1608a1514bc2b3---kifagiwum.pdfIn PDF document text
    • http://ourconn.com/userfiles/file/202107230552233056.pdfIn PDF document text
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/a13c8953bbdd4ad53d3e489dd4ba5379/79030950059.pdfIn PDF document text
    • http://bhs1966maui.com/clients/64750/File/55895631661.pdfIn PDF document text
    • https://soba05.org/wp-content/plugins/super-forms/uploads/php/files/a090e58955fed160aca0fe873582c437/48312059853.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1608572b077cb7---37548231309.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608b4da9c1ea8---60131623280.pdfIn PDF document text
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba8cb509d22---ximanerisolufanovixepafem.pdfIn PDF document text
    • http://svenstavik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160960434ce261---61316180837.pdfIn PDF document text
    • https://nhaccugiare24h.com/uploads/userfiles/file/45310552500.pdfIn PDF document text
    • http://alpha-cp.com/userfiles/file/33161193505.pdfIn PDF document text
    • http://patroha.hu/file/67024891152.pdfIn PDF document text
    • http://campfirewtx.org/userfiles/file/zujaponavovof.pdfIn PDF document text
    • http://golfproradost.cz/webpagebuilder/ckfinder/userfiles/files/xifidiwoxurapefebixeva.pdfIn PDF document text
    • http://acecaalcoy.com/userfiles/file/41133375178.pdfIn PDF document text
    • https://vieclamday.com/userfiles/file/luvawaje.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=que+quiere+decir+como+agua+para+chocolatePDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000510da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x510DA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000528ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x528EC 19316 bytes
SHA-256: 2cdd96fcc643724aecfa607e0eb267d986841dfdd030982faef65a4fccb3087f
font_02_sfnt_off00055a1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x55A1A 10996 bytes
SHA-256: 7e9afa5d8ba31df77c37e05f70aaf2e938b0bad9d545da632c977b659fb59af9