Malicious PDF — malware analysis report

Static analysis result for SHA-256 25056d5ca6a01624…

MALICIOUS

PDF

76.7 KB Created: 2021-09-01 21:26:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2057a6e4cd7631e912865356fee5128c SHA-1: b5dbfe7028506cc8a7f5eb9e0d33efee316e10d7 SHA-256: 25056d5ca6a016246a7029fdae4f254aca9501e39b038a95170d6b08d53f4fac
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to various domains, many of which appear to be compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of multiple external URIs and a link farm heuristic suggests the primary purpose is to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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 http://eng.sut.ac.th/tce/2016/administrator/ckfinder/userfiles/files/94352457670.pdf
    • https://cavalier-hundezucht.ch/userfiles/file/79870151692.pdf
    • http://motorlustor.net/userfiles/file/3212017816.pdf
    • http://ammk.sk/userfiles/file/45765902581.pdf
    • http://superpart.com/files/48049214415.pdf
    • https://drivetripper.com/userfiles2020/files/kevulab.pdf
    • http://ekotronic.eu/files/file/10125238434.pdf
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160ace37ff1910---wopazili.pdf
    • http://bobas24.pl/Upload/file/kokikukituro.pdf
    • http://mmdplus.com/userfiles/files/20210601_101741.pdf
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/dnbn00k0do1n1hu0rjhdqfbh11/punubixigigizagoguvo.pdf
    • http://noithatnhapkhaugiasi.com/luutru/files/dobipijovazikog.pdf
    • http://thebaileyfamilyreunion.com/clients/6/6f/6f45d7e5c9279c15d0bd3a3fa6949618/File/21151952001.pdf
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/cb38bab45e5dc9115b2871ff4d5581c2/deluforunowasovu.pdf
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f0f5431cd7---74889962639.pdf
    • https://sayurmateng.com/contents//files/kasute.pdf
    • https://maxflowfans.com/userfiles/file/rosupogaxubikonobozib.pdf
    • http://www.grupoaccs.net/ckfinder/userfiles/files/8957980781.pdf
    • http://tieclangman.com/Images_upload/files/wudunezumim.pdf
    • http://aarogyamedico.com/userfiles/file/35667724589.pdf
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/1cc84c9ee27a21b4dc37d41845c02239/gasobewujadofenebaf.pdf
    • http://insightonafrica.in/userfiles/file/20664449298.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=think+is+a+verb
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bfd4.bin
568713415a612b40d7d798c5fe0fd90d9e6657bcc0e866a6cb3f94adb786d49e
pdf-font-stream PDF embedded font (sfnt) at offset 0xBFD4 20400 bytes
font_01_sfnt_off0000f56c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF56C 16792 bytes
font_02_sfnt_off00010d83.bin
502548a5f254e6d50ba2e4299fb953c0f4878e96886f783c458dfcabc890d3fe
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D83 10200 bytes