Malicious PDF — malware analysis report

Static analysis result for SHA-256 53efbdcbad71b5d1…

MALICIOUS

PDF

83.1 KB Created: 2021-09-01 23:16:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: cb94555bbedb844cb55d14358a067bcb SHA-1: ba03e1b60140f49a044252ee53713d2d4874e0e8 SHA-256: 53efbdcbad71b5d181bd4c8af0855a079a376d3326cc4c638b90153f0d392a77
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to other PDF files hosted on compromised websites, indicating a link farm likely used for SEO poisoning or to distribute further malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9983

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://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/oom0kma38t39p69eosbv9gia9t/77146529034.pdf In PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160cf7fe8b43cc---61199948810.pdfIn PDF document text
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/cudgkoo20g8l4n72s5gt3gmvj4/91789279437.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160873abe05e1d---purewafinovu.pdfIn PDF document text
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/7k8d5nhok359a73p9i7o425p0j/nosuxiburadorumemit.pdfIn PDF document text
    • http://grossfamilyreunion.com/clients/0/00/00c8ca1d7e0432e0ca4c178cf0a97985/File/16872939110.pdfIn PDF document text
    • http://jullien38.com/ressource/site-image/files/20318601561.pdfIn PDF document text
    • http://tavernadelsnoguers.com/wp-content/plugins/super-forms/uploads/php/files/13b66ae9a69b9e404b082d1fac68cd65/zaduvenakop.pdfIn PDF document text
    • http://elitvorota.ru/f/file/41003332854.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/160859d4e6fdd6---85273823077.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e3115d5f24---59926019968.pdfIn PDF document text
    • https://www.tunnel.de/files/uploaded/file/zenipumirugeje.pdfIn PDF document text
    • https://southtours.com/wp-content/plugins/super-forms/uploads/php/files/b7c2u8dm7hhv73da22grv2k19n/gixutajidebavodug.pdfIn PDF document text
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/0def5881f5a40ff5d2cecad934281259/fenavexovotuforaropis.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/lpk3336ofpg3ingbkaf8r67sp7/21494389097.pdfIn PDF document text
    • http://jainfarms.com/uploads/vokowufidagexeravaju.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070ff07701e7---kojuxefag.pdfIn PDF document text
    • https://himalayanwanderer.com/himalayan/userfiles/files/66885687567.pdfIn PDF document text
    • http://chinawin-consult.com/userfiles/lesegomiwet.pdfIn PDF document text
    • http://raunlarose.us/wp-content/plugins/formcraft/file-upload/server/content/files/160711d407c671---gutivativolakuve.pdfIn PDF document text
    • https://polskieplytki.com/wp-content/plugins/super-forms/uploads/php/files/3493342801bb758fa422263bdbd2645b/6251182601.pdfIn PDF document text
    • https://asiaviews.org/wp-content/plugins/super-forms/uploads/php/files/opjbisktbf5rk6hkvbrqa6ce65/babapodurefogiwazivaji.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1608d2b1bc7864---vivilu.pdfIn PDF document text
    • http://anhuishangbiao.com/upload_fck/file/2021-6-7/20210607182215980086.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/794mjtnj5e7340isitkp92c07j/kibodo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=casteism+in+india+pptPDF 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_off0000e1fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1FA 17256 bytes
SHA-256: f5f07e44ffc03cefa5b0692e1475c6ac610b4b4b5ee45afcf10426121f3a8f34
font_01_sfnt_off00010e74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E74 10320 bytes
SHA-256: 92f1f443f0260e97f04291d6281d1426ff1a0bfa4a26ca143653a9545774657c
font_02_sfnt_off000125b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125B4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1