Malicious PDF — malware analysis report

Static analysis result for SHA-256 d7aa2895adaa77c9…

MALICIOUS

PDF

77.5 KB Created: 2021-08-14 22:57:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: d14c74c5e03f6f874c1332f4cd487132 SHA-1: 584c55fb199ff246cf09ef3dcb4f832cc83a9cc3 SHA-256: d7aa2895adaa77c99a7a468bae649fbd12e6b913a1653f1db9135be036045f16
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 other PDF files hosted on various websites, many of which appear to be compromised CMS uploads. The ML classifier strongly indicated maliciousness, and the heuristic firings suggest this is a common technique for distributing malicious content or manipulating search engine results. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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 http://www.maderas-navarro.com/ckfinder/userfiles/files/newipasasudenufozax.pdf In PDF document text
    • https://xanbiente.de/userfiles/file/73893771273.pdfIn PDF document text
    • http://aj-freight.com/ckfinder/userfiles/files/94500967813.pdfIn PDF document text
    • https://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/nihai613gvvu1ddafjauck6uqc/xonobukexutukuli.pdfIn PDF document text
    • http://delawaretravelmedicine.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083b648d5e14---1951177270.pdfIn PDF document text
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/a4udgqskt8c33l081q8k1ralkm/pitekelegugenoj.pdfIn PDF document text
    • http://diegogenna.it/userfiles/files/favesawig.pdfIn PDF document text
    • https://hydratrend.com/application/third_party/ckfinder/userfiles/files/temifarefatuzexuxebir.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fd43b78d2d---1781780874.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b883361d30e---13136479632.pdfIn PDF document text
    • http://servicedental.it/userfiles/files/39259169204.pdfIn PDF document text
    • https://petek.biz/resimler/files/lozilaruzedo.pdfIn PDF document text
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/cje0savhpeunmrqdohc6cta3in/59551784204.pdfIn PDF document text
    • https://tidaksusah.com/contents//files/dokufogoweme.pdfIn PDF document text
    • http://bainihu.com/upfiles/editor/files/potoza.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160faa72aea3b2---80815438073.pdfIn PDF document text
    • http://weymouthhighschoolclassof62.com/clients/5/50/50fe23896e84432c97ff20d680692bb9/File/najuzumapabukivole.pdfIn PDF document text
    • https://sealskinz.ru/files/file/sivubulana.pdfIn PDF document text
    • http://kargiskola.ge/myadmin/ckeditor/ckfinder/userfiles/files/gewenizix.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/973e5ba9bf1b0908f5d71f131732851f/pagaritirukizaxuxeguje.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/pilsq3at5gp4v185eese3ao0no/relowi.pdfIn PDF document text
    • http://oishisushigd.com/uploads/files/fivuwigozakovixa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=converter+pdf+em+word+gr%C3%A1tis+portugu%C3%AAsPDF link annotation
    • 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_off0000c817.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC817 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e02e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE02E 11256 bytes
SHA-256: 471273030022bdac36d3109b04c48d1bd3536ef8a646ae77ad2a3169ae1716a9
font_02_sfnt_off0000fa37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA37 17928 bytes
SHA-256: bb6ab0f76db531a5762ba06d52a67af358da10fdba10027db08b8ff3bedd2803