Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b6b4c7af67cf9bf…

MALICIOUS

PDF

97.4 KB Created: 2021-07-06 21:58:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 5f09b25f29441295ccfbdfa58f211e88 SHA-1: 4f83467f0b46e3b948e935742a4c3653391418cc SHA-256: 4b6b4c7af67cf9bf70630d00139cef62df652e3c57a7c9b8047902ee6213715a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to compromised CMS upload storage and disposable hosting, suggesting a link farm designed to redirect users to potentially harmful sites. The presence of external URI heuristics further supports the attack pattern of luring users to external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9930

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://huntic.ru/uplcv?utm_term=most+common+regular+verbs+in+english PDF link annotation
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ae01ee2f91---66641111915.pdfIn PDF document text
    • http://zoncmswebsitebeheer.nl/files/editor/file/7433149115.pdfIn PDF document text
    • http://bc-arman.kz/ckfinder/userfiles/files/98709918959.pdfIn PDF document text
    • https://www.ideaklinik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160748142200c4---wovosebovamenewerixeki.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160bb52a78a975---71597922110.pdfIn PDF document text
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/4aa4a4a03ec716301b58c6bad745e79c/7515072623.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/81so638kj5ubn9v4mc6a0ju6dp/xojojesotowitotu.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b73708148f1---97135319728.pdfIn PDF document text
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/7dpo99p8frej05aubm66djhnh6/31018740515.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090c572a6c25---90766371947.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160e3251124693---59843332636.pdfIn PDF document text
    • http://nutranghongngoc.com/media/ftp/file/40984860662.pdfIn PDF document text
    • https://naucharts.com/ckfinder/userfiles/files/49803816664.pdfIn PDF document text
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16084aa5309c01---pekezexapefibeda.pdfIn PDF document text
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/5444ac056fd69a1ce7ceb78e77055a4a/5418129415.pdfIn PDF document text
    • http://cuatudongbinhduong.net/uploads/files/38503405344.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160c607665c007---61714009196.pdfIn PDF document text
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/betimejekerifojojigewifer.pdfIn PDF document text
    • http://villa-margherita.biz/userfiles/files/63843256771.pdfIn PDF document text
    • http://lpc2529.com/piceditor/file/15572819838.pdfIn PDF document text
    • http://ildungrice.com/fileupload/fckeditor/file/7649294266.pdfIn PDF document text
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/9d12d3691285021f6ddfd8ea30e53ee0/33976579126.pdfIn PDF document text
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160ceba8a5296a---89833753804.pdfIn PDF document text
    • http://villa-carlshorst.de/sites/default/files/file/ledebevebedodukelekupog.pdfIn PDF document text
    • http://bakoca.hu/files/file/zativ.pdfIn PDF document text
    • 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_off000116e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116E8 10976 bytes
SHA-256: 781dbe6d7e2033afc2cc36a9e11173634e4e20b2966c19e6b38845a080ea65aa
font_01_sfnt_off0001303a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1303A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001484c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1484C 18284 bytes
SHA-256: 3a0a8190fea7263ce047ded729fd1c95ca0e86bc65b3af4aa547a055f32c13e7