Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3b861752f7222c7…

MALICIOUS

PDF

84.9 KB Created: 2021-09-06 07:09:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 84e31980ba486dcc1c49ca21e0a5d082 SHA-1: 7aac533a71974f8248fb13c74a5fe3da39cf6849 SHA-256: b3b861752f7222c7b03d26892703b7848c9e836c81f548fe02c6563379f65e27
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to potentially compromised websites or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of external URIs and link farms on compromised CMS uploads strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://queure.ru/uplcv?utm_term=remstar+c+flex+manual PDF link annotation
    • http://bioterapiazabiegi.pl/obrazy/file/24748639297.pdfIn PDF document text
    • http://hongshengfish.com/uploadfiles/2021051222322426972.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b40b75450ad---leradalekitudopali.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607aba171bd1d---pofukasosu.pdfIn PDF document text
    • http://aven.su/userfiles/file/nogamuboli.pdfIn PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/n8a0g290lg6fb3dmd5nk4vr27m/kalufogujumome.pdfIn PDF document text
    • http://braciszewska-klimek.pl/fck_files/file/56242483524.pdfIn PDF document text
    • http://baohanhranghm.com/upload/img/files/80372799858.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609eaeef19ba0---fedajevomu.pdfIn PDF document text
    • http://vidol.nl/userfiles/file/wuzagivudiwu.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/q7ljjlji3kti0dq0mbrdi4jbf1/36584115672.pdfIn PDF document text
    • http://fine-cottage.ru/userfiles/file/48248647928.pdfIn PDF document text
    • http://lamachine.nl/userfiles/file/52172838282.pdfIn PDF document text
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/a040a589d691824f6c8371706260708e/33282486923.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fa6933a8d7---fevowewelunumodijisi.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160ac38fe650e9---korekonu.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/99d43opldh4nbu4aam92e8hsqg/17589946133.pdfIn PDF document text
    • http://sindikat777.ru/ckeditor/ckfinder/core/connector/php/uploads/files/83991475063.pdfIn PDF document text
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/990f24a89d179dba659f049d6d09c8eb/70371501087.pdfIn PDF document text
    • https://apparel.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/d821cfaf4b36e9d0e31abd7ad05c24ae/87280962457.pdfIn PDF document text
    • https://tucarrorentacar.co/ckfinder/userfiles/files/68442980998.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/160a2e869e7124---40403869057.pdfIn PDF document text
    • https://khabul.mn/mmpa/userfiles/files/zoxupolexanudaz.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/161107a064eb62---24864422480.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_off0000e419.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE419 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fc2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC2B 19064 bytes
SHA-256: e9e5b93be4b8eb566a8030ec388a29205b597737bb2916f699b7210e041cc473
font_02_sfnt_off00012e69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E69 10532 bytes
SHA-256: 51f1a2f347790179382a4ad72ce8cb4d61dc7b4026c850c46264ddacb06d6d90