Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca0b3123aeb69396…

MALICIOUS

PDF

76.1 KB Created: 2021-10-05 19:22:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: d0d51ed54c17f5babc59ecb816c28014 SHA-1: 672066749765160d74dde56e895fe9066234aebc SHA-256: ca0b3123aeb6939600384b1a40df3c8d4b8051f9e9aa89b1c7ea330d3a9e9a09
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised CMS upload directories, suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is heavily obfuscated and unreadable, but the presence of link farms and compromised hosting is sufficient evidence for the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 https://medvor.ru/uplcv?utm_term=two+angles+that+can+be+trisected+with+a+straightedge+and+compass+are PDF link annotation
    • https://curewelldiabetes.com/userfiles/file/sazupelikiwubalukidagit.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/16158c08179f70---kusopitelivebirumufix.pdfIn PDF document text
    • https://koncnc.com/genelresimler/file/32305553060.pdfIn PDF document text
    • http://wolfpackbasketballacademy.com/content_docs/75079368254.pdfIn PDF document text
    • http://twilaw.com/files/files/95924735028.pdfIn PDF document text
    • https://dpdpunjabi.myskoolapp.com/FCKeditor/FCKimgUpload/file/sowopimozudigo.pdfIn PDF document text
    • https://scalper.ir/data/files/file/40336877319.pdfIn PDF document text
    • http://haciogullari.com/depo/sayfaresim/file/sikuwedenukonuse.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/161445127c1e85---romifidedut.pdfIn PDF document text
    • http://wonikquartz.com/upload/editor/file/1631274003.pdfIn PDF document text
    • https://pataniforum.com/admin/jquery/ckfinder/userfiles/files/15426332182.pdfIn PDF document text
    • http://acunambalaj.com/adenoto/upload/files/lolilemujukez.pdfIn PDF document text
    • http://aeon-dev.com/uploads/files/202109151855563899.pdfIn PDF document text
    • http://dreamsurgeryen.net/ckupload/files/12853820531.pdfIn PDF document text
    • http://korealabels.com/ckfinder/userfiles/files/bigivibikofo.pdfIn PDF document text
    • https://xn--80ag1a2a.xn--p1ai/files/file/8555077584.pdfIn PDF document text
    • http://salman-is.com/userfiles/file/wifukidotupulekex.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/16155c1dd496ca---vukarenivowemamosijafuv.pdfIn PDF document text
    • https://eksiliotomotiv.com/upload/ckfinder/files/22651780850.pdfIn PDF document text
    • http://asztalosweb.hu/userfiles/file/nojadudi.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_off0000bfd0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFD0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d7e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7E7 11152 bytes
SHA-256: 044297e16775ac1c3565be7050cb4dcf1090b32b2d4b0bd53648b4582b654965
font_02_sfnt_off0000f171.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF171 17984 bytes
SHA-256: 5b28c4ba71e03b997f35337fa1a302fd302027d09e0065361f4e5e13dd38e19e