Malicious PDF — malware analysis report

Static analysis result for SHA-256 99f6fe1f02589c47…

MALICIOUS

PDF

86.2 KB Created: 2021-06-10 17:50:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: fe603afdc8a9703237251f4c80ff43f4 SHA-1: c5cf619464871a08fefa1d0ff53b388ad267ea84 SHA-256: 99f6fe1f02589c472ac93cd4a6a56f73e36e45cdbb6275b2befd7321ba20ae48
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress sites or disposable domains, suggesting a link farm for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a common phishing or malware delivery tactic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://infrive.ru/uplcv?utm_term=boston+acoustics+review PDF link annotation
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ee2e80636d---woxorimovajavosunes.pdfIn PDF document text
    • http://karmand24.ir/basefile/ehotel724ir/files/xijimaxutaxarixenuzepobu.pdfIn PDF document text
    • https://acronimocostanzo.com/userfiles/file/vuvifovilugorimud.pdfIn PDF document text
    • http://hillcountryawningsandsunscreens.com/wp-content/plugins/formcraft/file-upload/server/content/files/160795e40b1c62---jonetaber.pdfIn PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609498ade69d3---nujuvovoziramupofi.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082569baaffd---wagexadarajubororodez.pdfIn PDF document text
    • http://narnivet.com/userfiles/files/nukazenizav.pdfIn PDF document text
    • https://mattress-leader.com/media/5926290500.pdfIn PDF document text
    • https://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/160741ab85198f---27600767415.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/e30c732e0b7404e3fb48939901865ee5/nuxaboperifumoxigidi.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1606f76451b2d7---zopifoz.pdfIn PDF document text
    • https://mszukam.pl/dat//file/10756800956.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160863f3edca4d---sijozolorupejuro.pdfIn PDF document text
    • https://xn----9sbccjdbca7cyaieg1a3j.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/160426ac3828e69c4bd1261bd69d68c9/milefovekilore.pdfIn PDF document text
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/v3plcqs290b2hdhv3rtmgbf9m6/mepopik.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011575.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11575 4964 bytes
SHA-256: 010e9d0da3d521aa9bd6b9d2c3def998e96ed31b1a2cbfd892b185e794932829
font_01_sfnt_off00012680.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12680 10948 bytes
SHA-256: d6b57d93e09307df34f3c6e0dfcb0ac37832b79d6d0ac46e1ff72d4e09ab824e