Malicious PDF — malware analysis report

Static analysis result for SHA-256 657b86508dd19d4c…

MALICIOUS

PDF

78.4 KB Created: 2021-09-03 21:49:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 62fa180e434f371b9245f3838ce757e6 SHA-1: c38ae6a517b1aabe95b14dda211a72e514a550f6 SHA-256: 657b86508dd19d4cf1d046014af81a62c3f559721e886b65b226f1e57ca09a34
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users to malicious content. The ML classifier strongly flagged this PDF as malicious. While no scripts were explicitly extracted, the structure and numerous external links suggest an attempt to deliver a second-stage payload or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • 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://medvor.ru/uplcv?utm_term=rumple+leed+test+pdf PDF link annotation
    • http://lroundup.com/clients/d/d7/d7466da0ad72d96b64793f89c518a0d9/File/ripijasatusukifomipenel.pdfIn PDF document text
    • https://candbco.com/ckfinder/userfiles/files/lobiw.pdfIn PDF document text
    • https://pet-fashion.ro/mm/file/rutasepiwokabesez.pdfIn PDF document text
    • https://bohemiamaestro.com/webpagebuilder/ckfinder/userfiles/files/89076260193.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/160a14578b27d6---gurijepamovijida.pdfIn PDF document text
    • https://toptenstudy.com/upload/files/BodyFile__611DCC36E5CA9.pdfIn PDF document text
    • http://mientrungland.net/uploads/image/files/29711447809.pdfIn PDF document text
    • http://artdealer.vn/upload/fckimagesfile/a9493c90a829a0a0b11b1637cfaba430.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16127651797ade---29108689417.pdfIn PDF document text
    • http://sgadsahodayatarntaran.org/sahodyatarntarannew/userfiles/file/23138714063.pdfIn PDF document text
    • http://minhquoc.vn/ckfinder/userfiles/files/8379902003.pdfIn PDF document text
    • http://espressoperfetto.nl/app/webroot/files/userfiles/files/38236083759.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a9c99b4bd87---99917008809.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608f940b0210c---60454130075.pdfIn PDF document text
    • http://doktor-okonski.pl/uploadimg/file/famubakuwutet.pdfIn PDF document text
    • https://bodegoncriollo.com/userfiles/file/32784775106.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d0b5abbb5f---62109326753.pdfIn PDF document text
    • http://twinmd.ru/userfiles/file/rujixasuligidafof.pdfIn PDF document text
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16076e7e013ecb---20452113830.pdfIn PDF document text
    • https://autotronics.vn/userfiles/file/zagovusemesepiza.pdfIn PDF document text
    • http://ordinate-ltd.com/file_media/file_image/file/talisoxinonozumi.pdfIn PDF document text
    • http://www.biotanika.pl/upload/file/zavovakolokarafu.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c978c096e7---bulatefinizujisewuboj.pdfIn PDF document text
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/q8ldmmkf1jc5ovm16mqdablnj5/50980608449.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_off0000c3cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3CF 10228 bytes
SHA-256: 104ea6b9f3dc6e24a0bbfec97f192341acfe242e103a3769961459d7145f9230
font_01_sfnt_off0000dacd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDACD 22052 bytes
SHA-256: 7888db93b22a474f0c4043631cfc149861746386105a39a179ec964b4dcfee1b
font_02_sfnt_off000113cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1