Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7cb8bcfbb563e6a…

MALICIOUS

PDF

88.8 KB Created: 2021-07-17 17:08:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 129d9fb80742561b339ca452981c1421 SHA-1: 909f6c7c2d1595d8109c98de122656041de4ee33 SHA-256: b7cb8bcfbb563e6aecf5483b99679c7cc11712143421d384a9097762a2d910b3
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous websites, many of which are hosted on compromised WordPress installations. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL analysis suggest a malicious document designed to lure users to external, potentially compromised, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://hostessima.pl/userfiles/file/sexigotigivevafuxirisagor.pdf In PDF document text
    • http://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160cc316ac1686---7309852944.pdfIn PDF document text
    • http://baovevietnam-vnss.com/upload/file/lazubekito.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/pi6i9vnmcna8m1oncjo7cggmst/mepip.pdfIn PDF document text
    • https://gfow.om/wp-content/plugins/super-forms/uploads/php/files/3bcq22so9j2sqbiou24kl3fe9t/43019738149.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/da0b78cbc1a3b435daaceb1727c6efda/39278950979.pdfIn PDF document text
    • https://3dreamvr.com/wp-content/plugins/super-forms/uploads/php/files/8c7a9a6cb863949122b956686387b74d/9631890568.pdfIn PDF document text
    • http://best-infosystems.com/userfiles/file/89133133356.pdfIn PDF document text
    • http://dobraukraina.org/sites/all/sites/dobraukraina.org/files/50460841510.pdfIn PDF document text
    • http://www.adarshvidhyasankul.org/userfilesfile/4840519202.pdfIn PDF document text
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609e9cd4b028e---25726451974.pdfIn PDF document text
    • http://anatolianlgs.com/userfiles/file/vuresazaxininemazolodob.pdfIn PDF document text
    • http://www.empresasdelimpeza.info/wp-content/plugins/formcraft/file-upload/server/content/files/16086ca6b33bd4---81316035510.pdfIn PDF document text
    • http://lab4050.com/upload/editor/file/lodisubemujevosamokip.pdfIn PDF document text
    • https://stagerightstaging.com/wp-content/plugins/super-forms/uploads/php/files/86ddb635a4d93ca0fbc3943e4f71788f/53375145868.pdfIn PDF document text
    • https://laser-arena.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1608c408de4cd9---83551460253.pdfIn PDF document text
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9b3b69ecd7---koxokudif.pdfIn PDF document text
    • https://shopexpert.com/app/webroot/files/userfiles/files/kimunatibovimesanufani.pdfIn PDF document text
    • https://aspirans.com/files/file/40322324400.pdfIn PDF document text
    • https://www.geo-decouverte.com/ck/ckfinder/userfiles/files/51914668197.pdfIn PDF document text
    • http://vickerycarpet.com/uploads/images//files/kujenenereki.pdfIn PDF document text
    • http://www.cbs-emballages.com/upload/file/83598335717.pdfIn PDF document text
    • http://cameralehiep.com/hinhanh_fckeditor/file/jomisemunurapaduw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=what+is+a+humanistic+therapistPDF 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_off0000f9f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9F6 17044 bytes
SHA-256: 82397de37b66d77508a1441ab6912918fe41d7f53c39318b4feaab0102da43fa
font_01_sfnt_off0001260a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1260A 10564 bytes
SHA-256: aa937408661680ebbb9ff56a73397a025d752af43be1a9e6ba22e2b8d29205c3
font_02_sfnt_off00013dfd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13DFD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1