Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4a83a7852b47ab2…

MALICIOUS

PDF

85.4 KB Created: 2021-06-09 07:12:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: f4f1d80b500b3a6e9811693edbd7a1e9 SHA-1: 2d6662ecd3cee7b25b6f61a55accb9e6b9dafe8e SHA-256: d4a83a7852b47ab23375da639e111e43bfdd92da8bfd2be7953d1e54e27f8aaa
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

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, with numerous embedded URLs pointing to compromised websites and disposable hosting, likely to distribute phishing content or further malware. The presence of external URIs and link farm heuristics strongly suggests a spearphishing attachment vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://synerhu.ru/uplcv?utm_term=100+most+common+english+verbs+list+pdf PDF link annotation
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/9fd9204371e6f68d5f42d7fe279f8680/rusebovogoseno.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d7f5049cf3---nakesepomajojalevud.pdfIn PDF document text
    • http://ackerviewguesthouse.com/userfiles/file/tolexijozusowupugejevuj.pdfIn PDF document text
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/cc4436d116c004a4614e9896e169a019/texolobi.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be4d5318fb6---fagomufalikodapexubok.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8a0c68b4e---66358709426.pdfIn PDF document text
    • http://daedukgs.com/admin/fckeditor/data/file/20210604015918.pdfIn PDF document text
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a33e159e24e---magupadijizubido.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076cf86ba182---xarumogilofinapozoweniben.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d751c4d246---55472751369.pdfIn PDF document text
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/d5a9120cdf5c6d380ca8fae2ff3f65f7/74885931816.pdfIn PDF document text
    • http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a4a2b800da---95029466125.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/tuwalojojupodejapu.pdfIn PDF document text
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606e10846b4e4---jozuwuz.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/xubibebazanudomepam.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00012942.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x12942 18924 bytes
SHA-256: 4f34a3b3d95c6468d8028d1484be9c64ceeee54e16bca6cb3c86dd122379c43e
font_00_sfnt_off0000ef92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF92 5656 bytes
SHA-256: 202c5588e85c671af688b276176894cdeb08b235f907187352d526896c6f8d68
font_01_sfnt_off000102af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102AF 11676 bytes
SHA-256: d93a4e8c7e3ea9b72ccbae4b7807f139bf8dd55279fa845d903dc8105169b465