Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef874eceaaad7196…

MALICIOUS

PDF

82.9 KB Created: 2021-08-27 19:57:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 890ee286cb932748b317d739fd0fe144 SHA-1: d5022e46f333d791e304ee0da779aef98d4f56bf SHA-256: ef874eceaaad7196ff422e3f224a39e860cbe0549b4464c7588d10b263700bf5
96 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 compromised WordPress sites and other domains, many of which host further PDF files. The ML classifier strongly indicated maliciousness, and the structure suggests an attempt to lure users to external malicious content, likely for phishing or malware delivery. No scripts were extracted, but the extensive use of compromised upload directories is a strong indicator of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://coretry.ru/uplcv?utm_term=propose+meaning+in+english PDF link annotation
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/238fed48fc7fd1e28fa51c3e53338471/pejoxexepinobif.pdfIn PDF document text
    • https://kubermatkaplay.com/ckfinder/userfiles/files/85929046804.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/pjunr2dh6l5usgl4mo92gp4dub/10810334951.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/16086ce93ae89a---paden.pdfIn PDF document text
    • http://poongdung.com/FileData/ckfinder/files/20210702_B8BB05A9F3AEC678.pdfIn PDF document text
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160932aa77b869---20517015938.pdfIn PDF document text
    • http://cofetariafraguta.ro/UserFiles/file/xomarabu.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/3fc8a97b96ad33bf57b8eade4fd09544/gusuboduxedepade.pdfIn PDF document text
    • https://cashmeredreams.com/wp-content/plugins/super-forms/uploads/php/files/5070ce2c080972059e55d5ce79c12df4/58645658545.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/161240bccbe423---feruvibixasegetokivonub.pdfIn PDF document text
    • http://metapolar.hu/tmp/89136523347.pdfIn PDF document text
    • http://ucity68.com/clients/e/ea/ea220da86df44fb0ae3b7c8e8295ccc1/File/79344322726.pdfIn PDF document text
    • https://www.projectorrentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa7bf3ef1b5---95822003627.pdfIn PDF document text
    • http://thebankcardservices.com/uploads/files/nojuxawaguxonorumizod.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac22339c274---92976300246.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b85fd9cc1fc---ferunemam.pdfIn PDF document text
    • https://pacantioquia.org/aym_image/files/7351703379.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e33ded92a4---40245643237.pdfIn PDF document text
    • https://genegurumiraclehealer.com/userfiles/file/97864297904.pdfIn PDF document text
    • http://cyclad.org/UserFiles/file/59476303089.pdfIn PDF document text
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/35b72e0f70d77a0bca12b92e789f584b/dekexawufoturoni.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_off0000de28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE28 17920 bytes
SHA-256: 30e17a16957cf41cd8d05775b6edbe4aa122e2eff770e5d06e6f8bf311060ffc
font_01_sfnt_off00010c32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C32 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012449.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12449 10600 bytes
SHA-256: 18bfe31d894d4cf1e8a6ca0c32ec777c7945fe5dc33172297bafba7b79d54729