Malicious PDF — malware analysis report

Static analysis result for SHA-256 3dd90ddbab1ea8f4…

MALICIOUS

PDF

81.5 KB Created: 2021-09-19 04:44:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 70028821a4ae7c7926dfa4419ff73248 SHA-1: 1aaa55ca1a104d8d2f6053619cc1528234657c59 SHA-256: 3dd90ddbab1ea8f4240b418c083830a3fc6f6e0ec4758f16c13b2ef54e58acd1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by a machine learning classifier and ClamAV, specifically flagged as a phishing trojan. Heuristics indicate the document functions as a link farm, directing users to multiple external websites, many of which are hosted on compromised CMS upload storage. The presence of embedded URLs and the nature of the heuristics strongly suggest an attempt to distribute malicious content or phish for information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cc4671445c---vosigeguradevafejop.pdf In PDF document text
    • https://futuresbuilder.net/dayafter/uploadimages/newsimages/file/lanetelonidogenajetas.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/161327f841a929---70185766699.pdfIn PDF document text
    • https://stpeterscbs.ca/ckfinder/userfiles/files/50649041292.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/1614209223a6dc---20554324067.pdfIn PDF document text
    • https://virtualpulse.eu/UserFiles/file/katogudonetoxigaz.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613acaed42289---58077249272.pdfIn PDF document text
    • http://southerncross-ex.com/images/blog/file/17395877699.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/5addc556224d8ab690faeaf7663bee15/12721319447.pdfIn PDF document text
    • http://ideviceplus.nl/app/webroot/files/userfiles/files/milajagatuwomesogipe.pdfIn PDF document text
    • http://getampedmag.com/ckfinder/userfiles/files/dowok.pdfIn PDF document text
    • https://eletvital.hu/uploads/files/54524604979.pdfIn PDF document text
    • http://fisioterapiasuzzara.it/userfiles/files/43112565460.pdfIn PDF document text
    • http://drumlockingclamp.com/FCK_Editor_Images/files/fosulamuvopu.pdfIn PDF document text
    • http://duef.ru/public/file/mupox.pdfIn PDF document text
    • http://northcity.rs/slike/files/80191341416.pdfIn PDF document text
    • http://ejmk.com/ej/upload/files/nelasujitelaxejumolaj.pdfIn PDF document text
    • https://anaksemut.com/contents/files/lifisigavuzimilad.pdfIn PDF document text
    • http://open.ua/uploads/ckeditor/files/puzurizajagexirepozesi.pdfIn PDF document text
    • http://trendstyleimage.com/uploads/ckfinder/userfiles/files/24591159510.pdfIn PDF document text
    • http://af.ssla.ru/images/fornews/files/37594826854.pdfIn PDF document text
    • http://oticonshop.net/ckfinder/userfiles/files/zunavunonulazilop.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=how+long+to+keep+cooked+chicken+in+refrigeratorPDF 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_off0000da31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA31 17500 bytes
SHA-256: 8c77c62bca00ace0a9ffd0648f3dee5b85346626a14b25b989c77af061b26b47
font_01_sfnt_off00010771.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10771 10900 bytes
SHA-256: 88e8b10dbe4ca2c47329ec31835e4ad9d385dcc49b2e3634a575c9d2caa327e9
font_02_sfnt_off00012069.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12069 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1