Malicious PDF — malware analysis report

Static analysis result for SHA-256 a55e6536b7f2f031…

MALICIOUS

PDF

79.0 KB Created: 2021-07-24 06:42:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 3774f966ab310cbf47c9bab7c8117bb4 SHA-1: f52c55fdee8500424109da9942d3e5caf48a8744 SHA-256: a55e6536b7f2f031bd23e025473942c6ffe0ff341758b354f32bec948c8bafff
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The document body is heavily obfuscated and unreadable, providing no direct content clues.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9631

Heuristics 6

  • 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.
  • External URI info PDF_URI
    PDF contains an external URL action
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://rts-3.ru/upload/files/femuraxep.pdf In PDF document text
    • http://megalabsrl.it/userfiles/files/zuxalekagida.pdfIn PDF document text
    • https://weeb.nu/userfiles/file/tavepizagapolu.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b5b1511671---52987273446.pdfIn PDF document text
    • http://dtcguild.org/clients/80367/File/kidudusa.pdfIn PDF document text
    • http://koreaseowon.com/ckupload/files/44354529822.pdfIn PDF document text
    • https://ceccarbotosani.ro/userfiles/file/3253342784.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/61070874524.pdfIn PDF document text
    • https://bahamianbrewery.com/ckfinder/userfiles/files/wamasojivomupizawiwot.pdfIn PDF document text
    • http://ingmarcofaedi.com/userfiles/files/30260096077.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/16098308c3c870---86311190477.pdfIn PDF document text
    • http://shreyaghoshal.com/konadnew/userfiles/file/73618940829.pdfIn PDF document text
    • https://sieuviet.net/webroot/img/files/49866169796.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/16095794b8bf34---12500989400.pdfIn PDF document text
    • http://www.centralperdana.com/file/36425613499.pdfIn PDF document text
    • http://arohitourandtravels.com/userfiles/file/37285488164.pdfIn PDF document text
    • http://howsonfamilyreunion.com/clients/5/57/57b8fe7d350e782a16e6afc8bdcd6467/File/6868163061.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/160799c940fc2c---25854944407.pdfIn PDF document text
    • https://autosaloncenter.com/uploads/file/sanovo.pdfIn PDF document text
    • http://n2nlah.org/UserFiles/file/ninezudakava.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607efd4537e9c---duzudeboxewutuwaderes.pdfIn PDF document text
    • https://uleshuzataruhaz.hu/files/file/wekasanixarerewonit.pdfIn PDF document text
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/079f632c967cb398283dc8e3c3305018/jedidigobedawakegax.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=okey+plus+chip+hilesiPDF link annotation
    • 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_off0000dda1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDA1 10216 bytes
SHA-256: 9a34eb0f79a369bbd85be7edfe1672a0c9fc6a411556dc2458076aed5ff93cac
font_01_sfnt_off0000f4bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4BF 18356 bytes
SHA-256: fcbabcf0ad26ac8e0e480a7d2d83e2e6de1231a4950ac56568bf827b33871632
font_02_sfnt_off000121f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1