Malicious PDF — malware analysis report

Static analysis result for SHA-256 b550404294ebc5cd…

MALICIOUS

PDF

90.0 KB Created: 2021-10-20 01:53:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: f8c763f62d61c970cc35bd6f2e85131b SHA-1: d5ff92a1729e280557b6c4f41ac377856ba53eeb SHA-256: b550404294ebc5cdb898b299ef8866ecf4fa2cdf369e6b53d10e8c3db4ecfdd9
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, characteristic of a link farm designed to redirect users to malicious sites. The document body is heavily obfuscated and unreadable, suggesting it serves as a container for these malicious links rather than user-facing content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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://wastran.ru/uplcv?utm_term=ver+novela+rubi+2004+capitulos+completos PDF link annotation
    • https://fluffy-chins.com/images/file/xasumanebatos.pdfIn PDF document text
    • http://moda-minulosti.cz/docs/momin/file/9928356171.pdfIn PDF document text
    • http://salukool.ee/upload/userfiles/file/zozilu.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1612f2245b5049---48143565809.pdfIn PDF document text
    • http://ranaghatpchsschool.org/userfiles/file/jijuwepiduvizu.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/161673f75444df---35985821147.pdfIn PDF document text
    • http://knupress.com/pds/editor/file/tuvurebozinowetilanid.pdfIn PDF document text
    • http://www.sctiec.com/up_files/FCK/file/44837701949.pdfIn PDF document text
    • http://www.anjhimayath.com/upload/file/39244537782.pdfIn PDF document text
    • http://neuchina.org/userfiles/file/69156634456.pdfIn PDF document text
    • http://www.ruben.pl/ckfinder/userfiles/files/94634425337.pdfIn PDF document text
    • http://ristoranteibucanieri.it/userfiles/files/bawoxoj.pdfIn PDF document text
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/1615dbf9209532---zokajugilevu.pdfIn PDF document text
    • https://mcgbaharat.com/userfiles/file/suzufukil.pdfIn PDF document text
    • https://alternatifhirdavat.com/upload/ckfinder/files/puguxenazonojiwajiludib.pdfIn PDF document text
    • https://toliveinchristjesus.ceosale.catholic.edu.au/application/third_party/ckfinder/userfiles/files/jolixezamekasidusizemi.pdfIn PDF document text
    • https://guruamardaspublicschool.com/userfiles/files/bevut.pdfIn PDF document text
    • http://turagent007.ru/userfiles/file/miburafegorepavo.pdfIn PDF document text
    • https://gulfsupremesa.com/ckfinder/userfiles/files/lufipameduwisi.pdfIn PDF document text
    • http://my-hustle.net/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/95801777144.pdfIn PDF document text
    • http://codienlanhtrangia.com/Images_upload/files/jafawilamopodenewemokuja.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_off0000ef3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF3F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010756.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10756 11128 bytes
SHA-256: e9364d940832a178ca51d2c8c54919dc28e628a3eb37d92c30e43af4e8ea09e6
font_02_sfnt_off00012120.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12120 21700 bytes
SHA-256: 6de98337832f881749944c1248c04d6c4f19ff3a52ec0a4b7f34f87c975b3856