Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b24980830ded8f9…

MALICIOUS

PDF

70.8 KB Created: 2021-09-08 07:30:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 3aa83d0b4296df149a8112ab7a1681ed SHA-1: c8b707fc8707940b28b84022942a1f602ab573fb SHA-256: 8b24980830ded8f9dfdc0022e58d94becb6f953c851f656e3a19d8bb75dbd026
96 Risk Score

Malware Insights

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

The PDF file contains a large number of external URIs, many of which point to compromised WordPress sites. The ML classifier strongly indicates maliciousness, and the structure suggests a link farm designed to redirect users to potentially malicious content or phishing sites. No scripts were extracted, but the overall pattern points to a spearphishing attachment used to lure users to external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://synerhu.ru/uplcv?utm_term=chemical+composition+of+carbon+steel+pdf PDF link annotation
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/161275b3f0c58f---8105381576.pdfIn PDF document text
    • https://www.reachcast.ca/wp-content/plugins/super-forms/uploads/php/files/1e7eb8f9422ea4dda9b29303f64fbb5b/lejibekaj.pdfIn PDF document text
    • http://nhadep30giay.com/uploads/image/files/34548507665.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160bba02c60f34---30251911232.pdfIn PDF document text
    • http://pileshoppen.dk/userfiles/file/mozawobebuvobug.pdfIn PDF document text
    • http://mashhadgardi724.ir/basefile/mashhadgardi724/files/xemomojinevebewugaturumur.pdfIn PDF document text
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/67ca04c845660f0cc15c9bb6dbc74e5e/59269730237.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083f71ae33d9---48765310008.pdfIn PDF document text
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/olc2q3989n5ldmcigo978j8n7u/zasag.pdfIn PDF document text
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085f16f0f369---pilenogojavexujeziwe.pdfIn PDF document text
    • http://fantalife.nl/userfiles/file/jafewepaxito.pdfIn PDF document text
    • http://hockeydh.com/files/ups/files/duxaj.pdfIn PDF document text
    • http://jhdljz.com/userfiles/file/1626122164.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/16094478021296---80919807686.pdfIn PDF document text
    • http://jainfarms.com/uploads/64775399604.pdfIn PDF document text
    • http://evo-models.com/uploads/userfiles/files/dikakofasozevesutifi.pdfIn PDF document text
    • https://aptitudeclass.com/ckfinder/userfiles/files/meferukowoxatimem.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16104bec87fe04---28693016952.pdfIn PDF document text
    • http://volareinmongolfiera.it/userfiles/files/20511992628.pdfIn PDF document text
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/mp45v2q3uia0kk4v0f37sk4jn0/67071794142.pdfIn PDF document text
    • https://robotics-institute.com/wp-content/plugins/super-forms/uploads/php/files/br9hhtte6hseh8oe3e1j9b6dfi/kinugobi.pdfIn PDF document text
    • http://china-miyaco.com/img/file/202188175118.pdfIn PDF document text
    • http://flirdining.com/uploads/files/bawewu.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_off0000b57c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB57C 15268 bytes
SHA-256: 5ea5b9d7805a613a9a356530391f85c78c4b0693359db27d5b869a59673ba970
font_01_sfnt_off0000dbeb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBEB 11056 bytes
SHA-256: d4816f06e3c6cfe5bcb71c102a6d68441c34bea5aa8b42a9f2e89ed73c02f8ed
font_02_sfnt_off0000f542.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF542 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1