Malicious PDF — malware analysis report

Static analysis result for SHA-256 28f94544c53e27cf…

MALICIOUS

PDF

71.4 KB Created: 2021-09-01 09:20:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: cf36b518a1840e85a51fc4b84e7dd06d SHA-1: 76f5b524c3229bf96bb9d18b00e5f8ae251cf0a4 SHA-256: 28f94544c53e27cfdc8318d808308140840e108acfdf42c6f8e16546a77e8512
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm hosted on multiple compromised WordPress sites, suggesting an attempt to distribute malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were directly extracted, the structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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://www.supercarrentalsofmiami.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084cd0306644---17646000926.pdf In PDF document text
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/16120fabf69805---wuvokive.pdfIn PDF document text
    • https://gamaconsultores.cl/upload/file/93296509381.pdfIn PDF document text
    • https://movingalpsfoundation.ch/userfiles/file/18490029138.pdfIn PDF document text
    • http://amazingindiaphotos.com/amazingindiaphotos//upload/fckimage/file/6480318036.pdfIn PDF document text
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160802e7fc589c---femajuwizininixugizusa.pdfIn PDF document text
    • http://leaders-adv.net/userfiles/file/pezaser.pdfIn PDF document text
    • http://gzperson.com/uploadfile/files/serobejebepux.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160ce97531a0b8---87476357046.pdfIn PDF document text
    • http://www.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b42ae57a392---mojisibazekuvaxusapu.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/ptng0ohh1pedoknubtmdlep70s/jajunibijir.pdfIn PDF document text
    • https://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/f9f1f2cd40d0994261a067436536a92b/76565950432.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b60f366975---3688996714.pdfIn PDF document text
    • http://compsult.net/userfiles/file/65288164746.pdfIn PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607418fa7dfa7---45168906383.pdfIn PDF document text
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/27e4b1956087f1e692469ee68a50ca70/donugovokininakikolamu.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16099caf9c2091---jivutelevuxowazuweke.pdfIn PDF document text
    • http://9meclinic.com/ckfinder/userfiles/files/velosixanepuwimo.pdfIn PDF document text
    • http://bestbelly.org/content/files/files/mofimurivajopitubelaf.pdfIn PDF document text
    • http://yuanjen.com/ckfinder/userfiles/files/jakofugagaminetekimew.pdfIn PDF document text
    • https://ceilford.org/wp-content/plugins/super-forms/uploads/php/files/47d50f69cdb512f362954c73a0c389f8/waxos.pdfIn PDF document text
    • http://rayer.cn/d/files/kidowubi.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16077737ee49f6---32840084609.pdfIn PDF document text
    • https://stijsr.com/userfiles/file/82576596044.pdfIn PDF document text
    • http://austintownfitch1980.com/clients/879833/File/timanibuvem.pdfIn PDF document text
    • http://proxima-design.cz/files/file/belemebobizogan.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+determine+domain+of+a+functionPDF 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_off0000b747.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB747 15648 bytes
SHA-256: bd06a41fc0105c2c6738e85799398fdf81682cce36f940bc3992d1b62f058a88
font_01_sfnt_off0000df87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF87 10600 bytes
SHA-256: 703582402494d21374ae50c85d50dbc16a43ea75d44cd947dcc5ac3acbbabb64
font_02_sfnt_off0000f7bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7BF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1