Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a09359d749d1340…

MALICIOUS

PDF

96.2 KB Created: 2021-05-03 21:59:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 991d08a0db98a7fc02b023faae656ca9 SHA-1: ac1dee7446e5efb474cbd3d3bc9e48e72ea6c411 SHA-256: 3a09359d749d134092a87818ffa15c64662a4841ca0d79514fe74990a3a534e7
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous links to external PDFs hosted on compromised websites, suggesting a link farm designed to distribute malware. The document body, though heavily obfuscated, appears to reference "Algebra 2 test answers chapter 6", a common lure for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://allamericannursing.com/userfiles/file/parabutiwinokenirawiw.pdf In PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1608a4dc6a6860---80969404201.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/84246803cf937a31d47bbdf6c4d36ab0/70012699846.pdfIn PDF document text
    • https://ceilford.org/wp-content/plugins/super-forms/uploads/php/files/bacd1375fbe8a4af98c9b14a096af71c/xafimeruxujuvivorolezope.pdfIn PDF document text
    • https://prosegik.com/wp-content/plugins/super-forms/uploads/php/files/faf12aae89b22d3838e2e76e851daec2/90803748171.pdfIn PDF document text
    • https://area34.info/wp-content/plugins/super-forms/uploads/php/files/q61o8sue8etf5h3v6kdignqgk0/nunoma.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/b34e57503931621b35d43e4335205d0d/sazaxaji.pdfIn PDF document text
    • https://realestateconnect.biz/wp-content/plugins/super-forms/uploads/php/files/od6sm311ere4cgm2n8u6ud2nn4/sitalajo.pdfIn PDF document text
    • https://agilitynd.com/wp-content/plugins/super-forms/uploads/php/files/33e553d4dd779ed2e17706c4929787b5/63585217370.pdfIn PDF document text
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c39dd112c7---rezosuzizamerolonu.pdfIn PDF document text
    • https://wecafephuket.com/wp-content/plugins/super-forms/uploads/php/files/oot98c4hemhcamdncbp8kc53ja/89517296175.pdfIn PDF document text
    • https://bonpetsupply.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076c6f81f2f8---41749788350.pdfIn PDF document text
    • https://agenciaboom.com/wp-content/plugins/super-forms/uploads/php/files/id3epju00ijlpucu77q2qjtgq3/45034653423.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb63548ade---guvipuresapawulabe.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/160741474c56d8---zinajonomiwasakiruzef.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1607864b1c2ce2---6996977573.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=algebra+2+test+answers+chapter+6PDF 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://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001158a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1158A 3664 bytes
SHA-256: a93b7fe94f31fbf2b86d4464c3626617385f27df6142c96152979f861afd324e
font_01_sfnt_off00012196.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12196 5704 bytes
SHA-256: 700372d4d78e2f176cdd82ef8cd8c9aa65eeaa14bf52a1b7514bc88dee419460
font_02_sfnt_off0001350e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1350E 11460 bytes
SHA-256: 279c3a0f331dccc693534aebc8e9e68638b985aeb00c78b3a9026e4416b8a0e9
font_03_sfnt_off00015c6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15C6D 16140 bytes
SHA-256: f3a8a2fd4c60fb61064cb28db2ee9ebd585e5978701651074f60c2748bd9b570

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