Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef13f66424042665…

MALICIOUS

PDF

78.6 KB Created: 2021-09-10 10:05:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 476fd9e847f682fbe4249b4c08474008 SHA-1: 9a3819ce7da0a5bfcd0705851151be1cde8e6383 SHA-256: ef13f664240426653927b85ff3095f7b3d16d96fb5802fdc63c49a258a920dc4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to compromised WordPress upload sites and other disposable hosting. The PDF's structure and embedded URLs suggest it is used to facilitate phishing or malware distribution by redirecting users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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://www.masozilina.sk/ckfinder/userfiles/files/pubisikuwagoxukapeman.pdf In PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/161318d213f3be---55563013781.pdfIn PDF document text
    • http://poddertradingandindustries.com/userfiles/file/tujokewoxixasezebagan.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea76870689---72668267527.pdfIn PDF document text
    • http://moscreen.in/cmsfiles/file/xevomorilebutavizev.pdfIn PDF document text
    • http://papinchess.ru/userfiles/file/72699368769.pdfIn PDF document text
    • http://inbiosa.eu/static/cfiles/files/85799041740.pdfIn PDF document text
    • http://www.sanjuktabanerjee.com/fckimages/file/masubigon.pdfIn PDF document text
    • http://drxzhang.com/userfiles/file/30239815073.pdfIn PDF document text
    • http://orikon.net/Images_upload/files/bedamavezuwe.pdfIn PDF document text
    • https://whiteplacard.com/UserFiles/file/lofofuzogodivuzuzetu.pdfIn PDF document text
    • https://www.sensiblemachines.com/ckfinder/core/connector/php/files/59260290557.pdfIn PDF document text
    • http://jplus-ag.com/upload/files/BodyFile__613A05141726D.pdfIn PDF document text
    • http://mlsconsulting.net/cms/files/File/66961743076.pdfIn PDF document text
    • http://mmckno2010.zkosuchdol.info/files/6737842525.pdfIn PDF document text
    • https://negaratoto.com/contents/files/pusipotuk.pdfIn PDF document text
    • http://kemnhapkhau.com/upload/files/zabufinubekexirade.pdfIn PDF document text
    • http://studiogiamberardino.it/userfiles/files/98602127891.pdfIn PDF document text
    • http://eternaseguros.net/files/files/rudof.pdfIn PDF document text
    • https://kolegium.inaheart.org/upload/files/33735475536.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135087bcad07---mexozujajigusinonevus.pdfIn PDF document text
    • http://bike-aholic.com/UserFiles/file/lopen.pdfIn PDF document text
    • http://prestopc.it/upload/file/92345076957.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=whatsapp+new+version+download+for+iphonePDF 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_off0000cf70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF70 17356 bytes
SHA-256: 375ed74e9a6cb75bdd7df48aa12c4b16ebf44aff51a452082e3105c9312f992b
font_01_sfnt_off0000fbe6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBE6 10740 bytes
SHA-256: 549d01c0f9eddb20f8d280f765006e6dbebb5202b140e734166ad34ff0c7d41f
font_02_sfnt_off00011495.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11495 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1