Malicious PDF — malware analysis report

Static analysis result for SHA-256 c88fd8cd9d6eaa8b…

MALICIOUS

PDF

92.1 KB Created: 2021-08-09 23:47:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 93b29ff939c97cffd4a31049f0031c76 SHA-1: 27057c10653b6e5328a4d1d1d763106d1625c309 SHA-256: c88fd8cd9d6eaa8b3efe3a9b0d26a81cec38ffde24fde5c171a53e5276648fe3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to potentially compromised websites, suggesting it's used to distribute phishing content or further malware. The presence of external URIs and link farm characteristics strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

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://inwebjor.ru/uplcv?utm_term=is+there+a+grace+period+for+car+inspection PDF link annotation
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607eddcda9191---39977473649.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160733f7bdbb5a---9988865379.pdfIn PDF document text
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f9074aa9045---8152765436.pdfIn PDF document text
    • http://kolasinprevoz.rs/slike/files/tekesopatumo.pdfIn PDF document text
    • http://studio-rivetti.it/userfiles/files/34611041397.pdfIn PDF document text
    • http://3sdent.com/upload/files/joniwadopunurovefusenu.pdfIn PDF document text
    • https://djennebeads.com/nbloom/fckuploads/file/bugozudikijajozizabaxe.pdfIn PDF document text
    • http://bajcsidavidfoto.com/_user/file/nuzowapofalibikazig.pdfIn PDF document text
    • http://areaengineeringsrl.eu/userfiles/files/16274296153.pdfIn PDF document text
    • http://monroe74.com/clients/871877/File/52020777854.pdfIn PDF document text
    • https://twfern.org/upload/ckfinder_temp/files/20210526203008.pdfIn PDF document text
    • https://e-midas.ro/files/file/78810904828.pdfIn PDF document text
    • https://vibangnhadat.com/uploads/files/fapivujodid.pdfIn PDF document text
    • http://partnercable.hu/files/7466442406.pdfIn PDF document text
    • http://progfin.pl/userfiles/file/43839689167.pdfIn PDF document text
    • http://bradleyhillsapartments.com/demo/uploads/contents/file/lupipexiradom.pdfIn PDF document text
    • https://aashianarealty.com/file/46685496217.pdfIn PDF document text
    • https://snqrsl.quebec/upload/editor/file/pisijakarefukawirijumi.pdfIn PDF document text
    • https://muratay.nl/userfiles/file/puradizijulukijebuponin.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c97fca1aa0.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f0fc09e713---26543168679.pdfIn PDF document text
    • http://bluedevils59.com/clients/862365/File/dafelipepolenowumufenod.pdfIn PDF document text
    • https://snoman.mb.ca/ckfinder/userfiles/files/basemizefinur.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_off00010436.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10436 17092 bytes
SHA-256: f0c2fd54a2464e4658f1941f87042a1e0ebcaf14b06b0671eac0edcef95b0c45
font_01_sfnt_off00013086.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13086 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001489d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1489D 10804 bytes
SHA-256: bb1eefc250244a2428d300337da61d443a69154afda7966d037d3f7af2fa7cd5