Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fb5b27930e922d2…

MALICIOUS

PDF

93.3 KB Created: 2021-06-28 10:56:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 7c39af51e8d5371244fc87c12b05a22d SHA-1: 6c6a299373b66edcce7d7989559f1d43fce40ae4 SHA-256: 4fb5b27930e922d2892146bc9400b24ae0c29e1d84883462665b257ab9f12b12
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites and disposable hosting, indicating a link farm designed to redirect users. ClamAV and ML classifiers confirm its malicious nature, specifically flagging it as a phishing trojan. The presence of external URIs and link farms suggests an attempt to lead the user to malicious content, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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 http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a24e0b802a5---sigovolumazi.pdf In PDF document text
    • http://brlairport.com/images/file/nogekesefetikodavob.pdfIn PDF document text
    • https://akarchlight.com/wp-content/plugins/super-forms/uploads/php/files/ec0fad40e82cdb68a5ea77b40f0eb06f/68677710697.pdfIn PDF document text
    • http://eurogeographyjournal.eu/admin/fckfiles/file/59432041020.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160775206801e6---muwemimup.pdfIn PDF document text
    • http://jar-ted.pl/file/90594025324.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160bcb5592b7e4---26048329388.pdfIn PDF document text
    • http://dianacb.cz/userfiles/file/56065174349.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/160944d667f48f---3552423145.pdfIn PDF document text
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160acef2a89219---9149321043.pdfIn PDF document text
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/ovsehgau9bm2f9o1sdas7g40ce/tofukelamudifadurimeg.pdfIn PDF document text
    • http://www.jobsincrete.gr/images/_user_na/file/74161659010.pdfIn PDF document text
    • http://holycrossyouthministryasp.org/clients/f/fa/fa15eac34f6f8ef5a8ada011ffef1578/File/maxelalexajijek.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab76127b410---96824274396.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0ls33j6afdklsuhnnkeer9r406/4356141382.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609f3268cf8e4---pesukikibarux.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/delajubabagolabulivopur.pdfIn PDF document text
    • http://heninrealty.com/userfiles/files/maluwimoxunaroge.pdfIn PDF document text
    • http://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7a95be679a---gegajukurapuwusenemegadi.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16079378960468---22875453904.pdfIn PDF document text
    • https://folklorebridge.eu/uploads/pictures/files/semopemijafamesidojixebe.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/e8ej9hqc83jvd5k6kgf7660ha7/77177006199.pdfIn PDF document text
    • https://jiptv.nl/wp-content/plugins/super-forms/uploads/php/files/j6ttjs6grlhu9jeuml5i2j4226/buxifedukuwowizevevu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=chief+clinical+informatics+officerPDF link annotation
    • https://mediaget.com/userfiles/files/nojawokejadufejenupowamu.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_off00010a37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A37 10632 bytes
SHA-256: 5135bc5dbdc153dd7716058ca4f9545018aca653a8fdc6eb449c2871871e25da
font_01_sfnt_off00012262.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12262 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013a74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A74 17288 bytes
SHA-256: 93c54c8ab63e69830b19a56849d1c62ac450644db49c351490d9d93d4925fccb