Malicious PDF — malware analysis report

Static analysis result for SHA-256 6a661df72c27c74c…

MALICIOUS

PDF

77.2 KB Created: 2021-09-24 03:46:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a06bde6c9a18bb2f48bf347bea480648 SHA-1: af8f96bf4846dbf876e792a62dd9e869aaa010d2 SHA-256: 6a661df72c27c74c39df4a8d2b1d36d8d622cc577f042fbbf9e8b313baf21015
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous URLs, many hosted on compromised WordPress sites, suggesting it functions as a link farm. The presence of 'utm_term' in one URL indicates a potential phishing or SEO manipulation tactic to drive traffic to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://chcial.ru/uplcv?utm_term=android+how+to+download+apps+to+sd+card PDF link annotation
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/3c51481b8326f9660377d5d76417d18d/89660342558.pdfIn PDF document text
    • https://csn-alliance.com/data/files/20187068020.pdfIn PDF document text
    • https://we-plus.tw/ckfinder/userfiles/files/texatigiza.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/16142cf4be22c1---foloxepakisor.pdfIn PDF document text
    • https://geniodelweb.com/file/vorerik.pdfIn PDF document text
    • http://dieta-plus.pl/userfiles/file/tewotenopiwagedaronoxekog.pdfIn PDF document text
    • https://intrigantka.ru/images/userfiles/file/58903847348.pdfIn PDF document text
    • http://www.singchai.co.th/ckfinder/userfiles/files/80794685642.pdfIn PDF document text
    • http://noithatsah.com/webroot/img/files/47370272662.pdfIn PDF document text
    • https://dammesliepas.lv/ckfinder/userfiles/files/731015750.pdfIn PDF document text
    • https://robustbrakes.com/administrator/imagetemp/file/18337983211.pdfIn PDF document text
    • http://peaceinsrilanka.lk/userfiles/file/91548788254.pdfIn PDF document text
    • http://vyveva.eu/UserFiles/File/dekibazixaberonujere.pdfIn PDF document text
    • http://www.cemeba.com/uploads/ckfinder/files/47185642511.pdfIn PDF document text
    • https://danielfelber.ch/userfiles/file/12123639897.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/1613c21802cf9c---42157014361.pdfIn PDF document text
    • http://mjengo.org/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/23298236732.pdfIn PDF document text
    • https://nezrenweb.com/calisma2/files/uploads/54465546495.pdfIn PDF document text
    • http://csc0731.com/userfiles/file/20210924072448_3grc6s.pdfIn PDF document text
    • http://savaksangida.com/resimler/files/14183663376.pdfIn PDF document text
    • https://capital-publishing.com/ckfinder/userfiles/files/sezapukegavutiki.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b55e84e86c---29144297164.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_off0000c57d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC57D 10548 bytes
SHA-256: 57c46e6494abb3c74adb9d3ab0db8321e3285223392f8d3a4f4f3b59522d77d3
font_01_sfnt_off0000dd85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD85 19340 bytes
SHA-256: 821f82d1eb5e5fa34cc8bf6482dee6e87242f6ca049ee0eb147198c725dad97d
font_02_sfnt_off00010ed2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ED2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1