Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1a5b35b745c65b7…

MALICIOUS

PDF

87.0 KB Created: 2021-09-04 16:12:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: bc20b6bd557d5aed3aa80cc533ce76fe SHA-1: 366b9a3b251492f521bc1bdd5d5f31405a1f2be0 SHA-256: b1a5b35b745c65b7f294f6dfe3da389070001f36b9659c6e8596ea97e5619cc3
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. It contains numerous embedded URLs pointing to compromised WordPress sites and other disposable hosting, suggesting a link farm designed to redirect users. The primary purpose appears to be directing users to potentially malicious external sites, aligning with spearphishing attachment tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://krisoc.ru/uplcv?utm_term=world+economic+forum+future+of+jobs+report+2017+pdf PDF link annotation
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/c93f020c92855495fb93554186f7ac53/39157031738.pdfIn PDF document text
    • http://tercovci.cz/files/file/sorapokidexugoxu.pdfIn PDF document text
    • http://tropo-design.com/ckfinder/userfiles/files/xolodenufonuve.pdfIn PDF document text
    • https://aznamaste.com/ckfinder/userfiles/files/68716726624.pdfIn PDF document text
    • https://thai-airpark.com/ckfinder/userfiles/files/botovu.pdfIn PDF document text
    • https://sharjahcements.com/images/bulk_images/files/kolorex.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606efdd3bb572---pevuwamifesokoj.pdfIn PDF document text
    • https://stef-nancy.fr/upload/document/mikizi.pdfIn PDF document text
    • http://britishcytology.org.uk/ckfinder/userfiles/files/sunerafigujasob.pdfIn PDF document text
    • http://makingthegradetexas.com/clients/d/d4/d4716c73f098ea79da165a2194b6736a/File/23107037969.pdfIn PDF document text
    • http://nfc.soo.jp/file/fuxarakowigolo.pdfIn PDF document text
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/4d6fffa2ac2e96fc11b7e178eb17295f/bipaveroguku.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/161033d71ab30e---fibalinafizunagozabi.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/krkfbsbsr4vbhup9o6qfr696uu/bugisakab.pdfIn PDF document text
    • http://bosch-service-center.ru/uploads/files/zufuzipamaxiwet.pdfIn PDF document text
    • http://handsonmontessoripk.com/userfiles/files/xisud.pdfIn PDF document text
    • http://randoquad72.fr/userfiles/file/nibowivasiwifud.pdfIn PDF document text
    • http://partnercable.hu/files/92072822570.pdfIn PDF document text
    • https://paperland.bg/uploads/file/83815807942.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612e6300456dc---7314027862.pdfIn PDF document text
    • http://www.saito-ken.jp/userdata/file/govefamof.pdfIn PDF document text
    • http://etpatatietpatata.com/userfiles/files/varifa.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_off0000eb7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB7E 11324 bytes
SHA-256: ee20f1940970402e3f4a5fb0d419c78b64cc388d5b7b1a6e6084e524da5b1d00
font_01_sfnt_off000105f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105F4 18444 bytes
SHA-256: cf3bd7c41b8399140dbb2935a9bb503aafe516cd59a37d5de8bd3c352cc2a6ec
font_02_sfnt_off00013604.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13604 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1