Malicious PDF — malware analysis report

Static analysis result for SHA-256 a499d11cfa5d4247…

MALICIOUS

PDF

79.2 KB Created: 2021-07-26 07:52:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: c052dc2993b9903fde5fc300014db9d0 SHA-1: a55c733a44384da977c0bd659a3344de3d5f4004 SHA-256: a499d11cfa5d424763d25f8e070aa5b4dbce68adf39d9ae78088106d7080d345
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to compromised WordPress upload directories and other disposable hosting, suggesting an attempt to redirect users to malicious content or phishing sites. The presence of multiple external URIs and link farm heuristics strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9909

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://cathyknightwaite.com/ckfinder/userfiles/files/55250321799.pdf In PDF document text
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098391c1efbf---wiruju.pdfIn PDF document text
    • http://www.sport-konyv.hu/userfiles/file/6501482143.pdfIn PDF document text
    • https://www.proctoloji.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607843b3f167f---76634089585.pdfIn PDF document text
    • http://jr-bang.com/uploadfiles/20210612195645.pdfIn PDF document text
    • http://rfinshaat.az/userfiles/file/duwoleb.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/rega6kvqtpc7i4vrc7u14i0mhj/21721421495.pdfIn PDF document text
    • https://medtek.vn/storage/file/mebonusixiforadudebemef.pdfIn PDF document text
    • http://fitnessklub-impuls.pl/uploads/assets/file/18752424883.pdfIn PDF document text
    • https://www.kbstephens.com/wp-content/plugins/super-forms/uploads/php/files/1c62839730fbe0fbed32c1ff0fdadebc/jijomanapezibiwonedajinof.pdfIn PDF document text
    • https://aprilboya.com/userfiles/file/64729693693.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7ef794c2d2---gugit.pdfIn PDF document text
    • https://minutesnap.com/wp-content/plugins/super-forms/uploads/php/files/75d3e3dbc0c20501abd9a2ada4e6e01f/6390652444.pdfIn PDF document text
    • http://sbsinternationalschool.org/sbsisnew/userfiles/file/58142318216.pdfIn PDF document text
    • http://ferramentabelleggia.it/public/file/tibus.pdfIn PDF document text
    • http://akvatoria.by/UserFiles/files/32026850732.pdfIn PDF document text
    • http://design-klasse.de/ckfinder/userfiles/files/40808452467.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7fc9aa74bd---8692359281.pdfIn PDF document text
    • http://atrsara.ir/resource/files/pezomijidajomubodizikos.pdfIn PDF document text
    • http://sistarelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dodinafi.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c8e79267186---tozifelekiwumamadowij.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607bb20b24d6f---79478707099.pdfIn PDF document text
    • http://drukarnia-warszawa.pl/pliki/file/fasuwuwavu.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075de45028f1---24935644700.pdfIn PDF document text
    • http://aydinservis.com/ckfinder/userfiles/files/viginetajalijolubitaz.pdfIn PDF document text
    • http://thaiboxes.com/piceditor/file/gadupafozetoxelerum.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=america+the+story+of+us+episode+2+revolution+worksheet+answersPDF 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_off0000cbe3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBE3 17524 bytes
SHA-256: 79927aea15e3e2e5c4e7cfdf20939d5e857f0e06f849021ed49a645c567d6b46
font_01_sfnt_off0000f9fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9FE 11444 bytes
SHA-256: b695e0a04342e8ea145b9a6890cc8425d062150154794903fed8a2bdb9cf84f3
font_02_sfnt_off00011500.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11500 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1