Malicious PDF — malware analysis report

Static analysis result for SHA-256 7d5b836f8100a47a…

MALICIOUS

PDF

86.1 KB Created: 2021-08-19 19:20:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 42abf9e591b5bc8dad96eafca5fcb8ce SHA-1: 99635e49baa22e669cfbb5f5bae1f0d616478885 SHA-256: 7d5b836f8100a47a5c5f6313caa7cd59eb698a43bd99fc07d927289aae5a1697
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics as a link farm hosted on compromised CMS uploads, with a high ML score and ClamAV detection. The embedded URLs point to various domains, many of which are likely compromised WordPress sites used to host PDF files. While no scripts were explicitly extracted, the nature of PDF link farms often involves JavaScript to facilitate redirection, hence the inclusion of T1059.007.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://ndt-ultratech.com/files/39205196328.pdf In PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16077c8bcdade0---nebenafotux.pdfIn PDF document text
    • https://www.kbstephens.com/wp-content/plugins/super-forms/uploads/php/files/12627fca16b83c4db1c8f245ac5725a1/komoxekulobamupijipetat.pdfIn PDF document text
    • http://www.ecvbrass.ch/user/web/file/70754394740.pdfIn PDF document text
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/f3693d7458398f3cc6ad79588c04ea78/donunogukesunefelomu.pdfIn PDF document text
    • http://symbioticlifetech.org/attfile/fckimg/file///2021080222748_1049679317.pdfIn PDF document text
    • http://kasintorn.com/images/upload/files/bozivolonefutajowev.pdfIn PDF document text
    • http://agataklimowska.pl/userfiles/file/59757695358.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/fo6bg16p9joa5p07ih2khru5v3/donegadomogapu.pdfIn PDF document text
    • https://stiff.pl/ckfinder/userfiles/files/12656742921.pdfIn PDF document text
    • http://hongshengfish.com/uploadfiles/2021051013195735103.pdfIn PDF document text
    • https://f27szerviz.hu/upload/files/95256368500.pdfIn PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/27703e2dadc1e462b77c5152000f5667/nabidekob.pdfIn PDF document text
    • http://fskyok.com/uploadfile/files/gasosexulidoxolirutavax.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fd525a3ade---gakani.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c549c4d5164---2214560831.pdfIn PDF document text
    • https://xenang-mitsubishi.com/fckupload/file/sakon.pdfIn PDF document text
    • https://wildarium.com/ckfinder/userfiles/files/81293336157.pdfIn PDF document text
    • https://lee-trading.tw/archive/upload/files/telidowo.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/fe0q9icvjfi643e8h40duhq9ar/safabozalululikutepe.pdfIn PDF document text
    • http://www.teeintact.com/admin/fckeditor/editor/filemanager/connectors/php/img/file/runapuwupexigusisuk.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cf299cd0893---90048215894.pdfIn PDF document text
    • https://munord.com/wp-content/plugins/super-forms/uploads/php/files/5631f2f57997c484a3602449505cf8b5/kapawemopi.pdfIn PDF document text
    • http://digjamaica.com/app/webroot/files/tomajefewegilufexoseg.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=how+many+questions+are+on+the+nc+dmv+written+testPDF 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_off0000eb57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB57 17240 bytes
SHA-256: 642d8ac6d83938ff43cfd5c36f8475d8974d3e6ec95a16dabec0231f2f1ce287
font_01_sfnt_off0001187f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1187F 11092 bytes
SHA-256: f045b03172d1e0f841a3018fecbcad33524e972db823a1d41e9dc5023e52c052
font_02_sfnt_off0001320d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1320D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1