Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef13dd628ec435f4…

MALICIOUS

PDF

84.7 KB Created: 2021-07-06 21:00:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 1384f86bf7c91b91660e24fa42143d70 SHA-1: 813db2b16d543fd3ea263cb7137df7563fa73c09 SHA-256: ef13dd628ec435f4a84ce1f64edbde7e9efc4e67b63876ce5b49ab8ebb31f25b
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF document was flagged by an ML classifier as malicious. It contains a link farm with numerous URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute malicious content or manipulate search engine results. The presence of these links indicates a potential spearphishing attachment vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://fullcolorspandoeken.nl/userfiles/file/dosexadirumota.pdf In PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/160982f7c35ba0---65732004554.pdfIn PDF document text
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/72c912cb99501f67d24e3c44e392cd69/tafoferofajeliku.pdfIn PDF document text
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/3o870jasn1svprnc35uusksrdp/xuzotuguxenoxad.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/odt5p0bmtfpk2u8qov6en7j715/9373969369.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607ae67f3506f---12488975888.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/9vmsd167unelhb76abe6njsern/goraselivevufotoxojode.pdfIn PDF document text
    • http://fhs76reunion.com/clients/0/00/009202203981f132fd14d012a57c0fe5/File/wulujumukamunixuro.pdfIn PDF document text
    • http://pogologistics.com/ckfinder/userfiles/files/fakajotefewuwes.pdfIn PDF document text
    • https://oddluzanie.net/userfiles/file/45988304890.pdfIn PDF document text
    • https://alatheir.com/atheirwsfiles/file/wozotagirit.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b64d3348d2e---wegufa.pdfIn PDF document text
    • http://filtrydokoparek.pl/img/all/gokexam.pdfIn PDF document text
    • http://cariboohose.com/userfiles/file/japuz.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/e45ff40a67f0163215b9ebd8dbe8dad8/29033446325.pdfIn PDF document text
    • https://investainternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fec0965566---85013009313.pdfIn PDF document text
    • http://everest-c.ru/ckfinder/userfiles/files/47948943947.pdfIn PDF document text
    • http://manixcnc.com/ckupload/files/vujixidov.pdfIn PDF document text
    • http://laulumaja.fi/ckfinder/userfiles/files/wuwebenujoref.pdfIn PDF document text
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/87ffdecdd9bd327ebdf6f19526404591/dixavimuba.pdfIn PDF document text
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa8162bfa7e---sesubevitorokoralivuxuliw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=doctor+of+humane+letters+salaryPDF 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_off0000e8ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8AB 10724 bytes
SHA-256: 92d3c9c8d404f60a211ebc2ad69f1f24d592706e221e351fcdafda9f246735f7
font_01_sfnt_off0001012d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1012D 17032 bytes
SHA-256: 520f9048b0c364575fa2eb55a8408f4c1fbb42b853f9b62b279cd8b9a3c592a8
font_02_sfnt_off00012d99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D99 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1