Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bc76901d2615ebc…

MALICIOUS

PDF

68.2 KB Created: 2021-09-15 16:24:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 2ae6781f87f5f5820cc14499dbbb2451 SHA-1: 4acea5becd6a7a9f9341453e48d95f5b0f363cd4 SHA-256: 4bc76901d2615ebc1eb56ef0075e6234515e29d8c28b894bea4bc498b665411d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics as containing a link farm pointing to potentially compromised WordPress upload storage. The ML classifier and ClamAV also identified it as malicious. While no scripts were explicitly extracted, the presence of numerous URLs, many hosted on what appear to be compromised sites, suggests a phishing or content redirection attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/98c2d84dcf1a8455d015973517766242/56481797996.pdf In PDF document text
    • http://bularz-auto.pl/images/userfiles/file/12198493775.pdfIn PDF document text
    • http://renknh.com/ckupload/files/lukulekijo.pdfIn PDF document text
    • https://grupa-energia.pl/attachments/file/13712360988.pdfIn PDF document text
    • http://onnetsolution.in/userfiles/file/vibiwurogiwa.pdfIn PDF document text
    • http://suurelepa.ee/data/file/65734356393.pdfIn PDF document text
    • http://labotinnghia.com/img/files/78998975012.pdfIn PDF document text
    • http://gro-felix.si/uploads/pulisedetofidodovumosug.pdfIn PDF document text
    • http://abaj.cz/UserFiles/File/81742274782.pdfIn PDF document text
    • http://jr-bang.com/uploadfiles/20210908023704.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/16136fffc677c2---ligik.pdfIn PDF document text
    • http://manpukulivermore.com/uploads/files/votaderezomorutalago.pdfIn PDF document text
    • http://euro520.net/userfiles/file/1631701691396413301.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/vuvuwalalenosemamed.pdfIn PDF document text
    • http://studiotecnicoligioni.com/userfiles/files/45135408766.pdfIn PDF document text
    • https://rosedreamholidayhomes.com/ckfinder/userfiles/files/bomelup.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/91e2323cdc9a11f391c7dc46e13d0c11/gawowasizipejimedijo.pdfIn PDF document text
    • http://conblocmanado.com/pics/file/maloduva.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/7301d9dcdaae5a3f2e25e6cc22274952/xudesomipigigususinir.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/6366806801.pdfIn PDF document text
    • http://ibookingkr.com/FileData/ckfinder/files/20210903_281269BEAA3768FE.pdfIn PDF document text
    • http://centrons.com/uploaded/file/668868972614026ca9b871.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=s10+plus+vs+iphone+12PDF 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_off0000ae31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE31 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c648.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC648 10524 bytes
SHA-256: 91e5fe3fd2d6b43379e300d0f89f0b17411e9ba955f60f0ecdc1e6576816ee68
font_02_sfnt_off0000de36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE36 14976 bytes
SHA-256: 3be6269e5563aed26f1def0148cbb098daa658fe3e61f1888aa19c106c00bc99