Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b9373ac766e5c18…

MALICIOUS

PDF

74.0 KB Created: 2021-09-20 07:18:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 97da3c3e5a67a5cd317aae33f5396a7c SHA-1: aedb831cb54ae6e3b877a5c830e75b7afee2b775 SHA-256: 7b9373ac766e5c1825bb1fbf6f3a0d7267eddf898d93be3d1eb8ebafaa1fdecb
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs pointing to compromised websites and disposable hosting, suggesting it functions as a link farm to distribute further malicious content or phish for information. The presence of external URI and link farm heuristics strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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
  • 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://garglob.ru/uplcv?utm_term=among+us+free+download+chromebook+unblocked PDF link annotation
    • http://dhleisure.com/ckupload/files/nikusamosibavovenuxuxif.pdfIn PDF document text
    • http://www.ktgroup.co.uk/ckfinder/userfiles/files/tipifirowa.pdfIn PDF document text
    • https://esperidiaogomes.com/userfiles/files/27076145738.pdfIn PDF document text
    • http://yushendesign.com/images_fck/file/1631103302.pdfIn PDF document text
    • http://savitaco.com/uploads/images/files/ganapedodigi.pdfIn PDF document text
    • http://pro-customer.de/userfiles/file/dogewugejasalebulox.pdfIn PDF document text
    • https://bio86.net/userfiles/fichiers/54210626598.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613afc47e5807---walovedodimeniduwujedigox.pdfIn PDF document text
    • https://basalyemek.com/ckfinder/userfiles/files/vepokorilesagov.pdfIn PDF document text
    • http://icsbc.ru/fuploader/file/guganonewusuladuzoke.pdfIn PDF document text
    • https://sabresources.com/FCKuploads/file/9791018094.pdfIn PDF document text
    • http://idealthailand.com/file_media/file_image/file/puluka.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/16147cb86be0d0---miwigugizuwakojufu.pdfIn PDF document text
    • https://www.vignolaweb.it/ckfinder/userfiles/files/rotuvojozelikurunidipevo.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/vbol8k4b9vtp5gkvca5k3848a5/48535237034.pdfIn PDF document text
    • http://gwtcs.org/Content/uploads/files/deraguwumis.pdfIn PDF document text
    • http://galluccifaibano.it/userfiles/file/82184954280.pdfIn PDF document text
    • http://yigang-lin.com/uploads/files/202109110149094848.pdfIn PDF document text
    • http://bfttacg.marketsearching.com/upload/files/18162556043.pdfIn PDF document text
    • http://manisafar.com/basefile/marcosafarir/files/vawulid.pdfIn PDF document text
    • http://metapolar.hu/tmp/33664035662.pdfIn PDF document text
    • http://matras-devison.ru/upload/file/zoditojevonev.pdfIn PDF document text
    • 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_off0000bcf9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCF9 17068 bytes
SHA-256: 2033decaa41fb7f940fb7ac3afe6477c0f2ab906a4a4d4f264526e609ada45f2
font_01_sfnt_off0000e8a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8A5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000100bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100BC 11132 bytes
SHA-256: cf7a38d495e7b67cd189b1fb5abe1325f708d668d8cb4b0b9e6ae9c9bc971476