Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5816cc6c153fabb…

MALICIOUS

PDF

79.0 KB Created: 2021-09-20 04:42:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 44a1c4b9213a55590ae0274b1ab0fd3f SHA-1: 3147e49c267eadd2b7007418bc94477285322b9c SHA-256: b5816cc6c153fabba5525f5930afe88b4237ae53045d282a22a2813225d8ac70
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous links to potentially compromised or disposable hosting sites, suggesting an attempt to lure users to malicious content. No scripts were extracted, but the presence of external URIs and link farm patterns strongly suggests a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://remoteyourstaff.com/calisma2/files/uploads/numiwabox.pdf In PDF document text
    • https://www.techsrollout.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cac185720b---75490121949.pdfIn PDF document text
    • https://xn--i1aam8cb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/825666ea59994fb0870258a04f51df3f/kidevumin.pdfIn PDF document text
    • http://futimisdev.com/userfiles/file/fijevalasewap.pdfIn PDF document text
    • http://clinicaveterinariasangiacomo.it/userfiles/files/ketatiratovobowefulem.pdfIn PDF document text
    • http://studiecarriere.it/uploads/file/57415696919.pdfIn PDF document text
    • http://tatagz.com/uploadfile/files/ketelapipo.pdfIn PDF document text
    • http://www.bluefashion.cz/ckfinder/userfiles/files/85146129311.pdfIn PDF document text
    • http://zvezda-rostov.ru/ckfinder/userfiles/files/69622592016.pdfIn PDF document text
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/e00be3195e5131f0a8f70262e3b07d3b/74174414278.pdfIn PDF document text
    • http://pagyesa.org/userfiles/file/20210914081431.pdfIn PDF document text
    • http://osc-pribor.ru/products_pictures/file/59872314435.pdfIn PDF document text
    • http://ryyw.com/upload/files/2021/09/202109031330304049.pdfIn PDF document text
    • https://strings97.hu/userfiles/file/96613158208.pdfIn PDF document text
    • http://heninrealty.com/userfiles/files/jejomobetowijufuwi.pdfIn PDF document text
    • http://sofia-es.tokyo/yamituki-n/uploads/files/68783861859.pdfIn PDF document text
    • http://terredellamagnagrecia.com/userfiles/files/56520782190.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/27624f4c45b6162f98eaf7c36680f740/buveronixakigibidab.pdfIn PDF document text
    • https://cr2tek.com/userfiles/Proj_Name/files/waxovufudagisu.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/75b929e08b1a0f9f348d6d9ee8203cb8/17746821848.pdfIn PDF document text
    • http://petra-dario.info/upload/datoteke/jikirekodiwesaja.pdfIn PDF document text
    • https://alhasooncorp.com/Files/files/32075698367.pdfIn PDF document text
    • http://costruzionibulagna.it/userfiles/files/vibufegexomibikufojoga.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=run+exe+on+android+2020PDF 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_off0000ceaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEAF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e6c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6C1 18324 bytes
SHA-256: 86d4ba4cf821bd343dba57a1ebd3da7e3b47e41a3af5d102b06e32f9b6fdbce7
font_02_sfnt_off00011672.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11672 10420 bytes
SHA-256: e1e2a73c9d4000345cb26aa4f0059b2ce870321767e7cccd6e12c103e0d26b81