Malicious PDF — malware analysis report

Static analysis result for SHA-256 aec4023d90fca009…

MALICIOUS

PDF

83.5 KB Created: 2021-06-25 16:12:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: e70c3e2759a4fd2b37c1e8481a3f4a65 SHA-1: 539e1ea776fbff244681b2d6d9c08034ee5199ab SHA-256: aec4023d90fca00909ca6c9bd78e6283d73e938c821c4703370b8aa291752df9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to distribute traffic or potentially lead to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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 http://wellfoto.cz/pictures/files/22959026208.pdf In PDF document text
    • http://antifftech.com/uploadfile/file///2021052113154810.pdfIn PDF document text
    • https://www.urban-quartz.co.uk/wp-content/plugins/super-forms/uploads/php/files/ab56e65ceef8c5f2a7606561552275dc/bisapopa.pdfIn PDF document text
    • https://windsbs.biz/files/file/lukudutuxigowoxis.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c77d5f3ee69---monog.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/9e3c264ee563e640454fcf8082480d22/15973176324.pdfIn PDF document text
    • http://stylekd.ru/files/71746559093.pdfIn PDF document text
    • http://centroolosprato.it/userfiles/files/29075628447.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160773530da6b4---65866469140.pdfIn PDF document text
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/532d1c629b595aa7da39ab91994d8cd3/meguriwapi.pdfIn PDF document text
    • https://mziagroup.com/wp-content/plugins/super-forms/uploads/php/files/m47qgrs0o7brf5un4matv05bof/32822384871.pdfIn PDF document text
    • https://wills.sg/wp-content/plugins/super-forms/uploads/php/files/a433b3fb335c529eeadb3a03d1c67fa0/7762870918.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d1b2ebe3cab---75994736310.pdfIn PDF document text
    • http://etcad.net/np/upfile/file/wukotevefofonosogox.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070b2544afe5---82678375106.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d84d061d58---dudifuwesuv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=how+to+remove+period+stain+from+sheetsPDF 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_off0000e31f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE31F 10860 bytes
SHA-256: 38c70ec6b3b21fbe978adccee6cffc7b8c4ce2264d0cb303269991fc3eae4970
font_01_sfnt_off0000fc0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC0B 16960 bytes
SHA-256: c3627f56d04e95e0ab94e8633407149e171f678af2ffdd69ff4e40b275c998a8
font_02_sfnt_off000127a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127A0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1