Malicious PDF — malware analysis report

Static analysis result for SHA-256 b39f77f82232283d…

MALICIOUS

PDF

82.8 KB Created: 2021-09-20 21:56:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 023deb704633dfaee38591c57699df59 SHA-1: cb30a7a088e0b78188dd2931c26657a511d551d5 SHA-256: b39f77f82232283d80e99990dfda1620da136d20d207fcfe68786bc27d2b452f
156 Risk Score

Malware Insights

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

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. It contains numerous links, many pointing to compromised WordPress upload storage and disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The document body is heavily obfuscated and unreadable, but the heuristics and URL analysis strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 https://cargobull.cz/res/file/fifavaxidapajum.pdf In PDF document text
    • http://vertracapital.com/uploads/files/18917399510.pdfIn PDF document text
    • https://xn--80aaijz0c.xn--p1ai/ckfinder/userfiles/files/64362936846.pdfIn PDF document text
    • https://leifs-auto.dk/images/file/44801446175.pdfIn PDF document text
    • http://solmoda.it/userfiles/files/96353954093.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16148909c7cc64---31029438408.pdfIn PDF document text
    • https://advance-pack.com/editor_upload/file/punofozovelorabakeriwedek.pdfIn PDF document text
    • http://perlawarmii.pl/userfiles/file/92857391635.pdfIn PDF document text
    • http://giovanniseneca.eu/userfiles/files/wakevukuriv.pdfIn PDF document text
    • http://lunaleo.pl/userfiles/file/javumawadapivuxubaj.pdfIn PDF document text
    • http://nirmalamathachurch.org/cms_uploads/image/file/tusegoridagud.pdfIn PDF document text
    • https://marcvandewiele.com/userfiles/file/pamapuxodatofabuvoko.pdfIn PDF document text
    • http://galaxyjewel.cn/uploadfile/files/23502527622.pdfIn PDF document text
    • http://bet-balance.com/userfiles/file/tivoveguxevenesorezegugi.pdfIn PDF document text
    • http://xn--djr00fsyfv0o5qgy9u.com/filespath/files/20210905002407.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/9095be4dfe5a203ffde3fef813d5df98/6074481466.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d75132c040---65809070918.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f028b6f75e---tipexepotenomumo.pdfIn PDF document text
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e414b4cee4---debipepufi.pdfIn PDF document text
    • https://westhigienia.hu/editor_up/linunukurotufufufir.pdfIn PDF document text
    • http://wawa757.com/uploads/files/66730226221.pdfIn PDF document text
    • https://khotelmarket.com/FileData/ckfinder/files/20210905_2926C436BD14CCEE.pdfIn PDF document text
    • https://cornerstonelaw.eu/userfiles/file/16882544330.pdfIn PDF document text
    • http://jyjjapan.jp/files/ckeditor/files/kofilupozojofevirat.pdfIn PDF document text
    • http://arebiatours.com/uploads/files/42558120095.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=oziexplorer+android+mapsPDF 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_off0000df55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF55 17780 bytes
SHA-256: f94e61f23d455480e9fc766329b10d41be8045199d3c8a7bba2bb282be9d48a0
font_01_sfnt_off00010da3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DA3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000125ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125BA 10644 bytes
SHA-256: 1dc6449a2d21fc3dfc1faeab78933c4694095f3e91d61cebcd64c57ff24aec09