Malicious PDF — malware analysis report

Static analysis result for SHA-256 dac71f4d316cdcef…

MALICIOUS

PDF

89.2 KB Created: 2021-09-06 22:47:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: a58e0cf6e7b001ad1c0b023c0b4c53a2 SHA-1: 7f1c1db22396aac86b4a109da698795e7b9b4d36 SHA-256: dac71f4d316cdcef43f5de094c40df1bc4901ca2ea402c263f40500526dc4f08
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to manipulate search engine results or phish users. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://inwebjor.ru/uplcv?utm_term=pneumatologia+pdf+cpad PDF link annotation
    • https://vibangnhadat.com/uploads/files/nujeweriwalitidupexa.pdfIn PDF document text
    • http://akvari-um.ru/userfiles/file/41881056661.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/9dc83bec9f831fcb68c35d14c7662fb3/binaponodokolazepaw.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d7077631c20---61363708810.pdfIn PDF document text
    • http://abwcoliseum.com/uploads/files/26021110633.pdfIn PDF document text
    • http://boldino-hotel.com/ckfinder/userfiles/files/lumikozatolarofawi.pdfIn PDF document text
    • http://jingluo.net/uploadfiles/files/jilovep.pdfIn PDF document text
    • http://preserveproperties.com/userfiles/files/guzuw.pdfIn PDF document text
    • http://nanobubblevietnam.com/uploads/userfiles/file/mamavugiw.pdfIn PDF document text
    • http://ipublicity.cz/data/file/mopon.pdfIn PDF document text
    • http://kmbb.at/userfiles/file/tiretu.pdfIn PDF document text
    • http://demkapi.com/resimler/files/vusimexibere.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7a6363b9eb---poxib.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/sdn1ho01h3il8hr29f8hm0225m/12333254602.pdfIn PDF document text
    • http://nfc.soo.jp/file/fogamelerejodowutoxuvok.pdfIn PDF document text
    • https://kimcert.org/E/file/tobifirinepuforomomutosi.pdfIn PDF document text
    • http://upbfassadenbau.com/upload/file/legakovomime.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/5ef7a3c496aa0ad797a60f88a0d3c95a/vawefedudel.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/7a7grh62gsfdmsm2cbc7vmps1k/30343519345.pdfIn PDF document text
    • https://nguoixunghekiev.vn/userfiles/file/92592256078.pdfIn PDF document text
    • http://irths.com/upload_files/files/47470400123.pdfIn PDF document text
    • http://cbwmd.com/uploads/Files/dakosuposesoru.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16113e4ce23f76---domire.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_off0000eeed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEED 10796 bytes
SHA-256: 2048a785d5967fce3be76f73ecc8c63363a0b005f5b3f41f1dcd894c9a7c4605
font_01_sfnt_off0001078f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1078F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011fa1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FA1 20792 bytes
SHA-256: f319461d0881fdf447bc7e7c5bc2d66eeac6697618889029ec72f33aedbfa18a