Malicious PDF — malware analysis report

Static analysis result for SHA-256 81001ff0786fc87e…

MALICIOUS

PDF

71.5 KB Created: 2021-07-08 18:34:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 8a0bd5e12b8daf9e0fbebca456f11411 SHA-1: 94d5badebf99ac9d3ebfe497aa7cc1f1f7a9124a SHA-256: 81001ff0786fc87ea811d586f0bb0c1801111918e66774d8a10991a1a79dc786
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a malicious PDF containing embedded JavaScript, which is a common technique for delivering second-stage payloads. The PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicate that the document contains numerous links to external resources, many of which are hosted on compromised or disposable domains. The ML_NYX_PDF_MALICIOUS and CLAMAV_DETECTION heuristics further confirm the malicious nature of the file, with ClamAV identifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://pc75.net/upfiles/file/1623318302.pdf In PDF document text
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/ed6a23336b3be0f2f82ac703dd6df372/sunuza.pdfIn PDF document text
    • https://dimensioninteractive.com/WYSIWYGImage/file/24223242215.pdfIn PDF document text
    • http://yuanjen.com/ckfinder/userfiles/files/57613682467.pdfIn PDF document text
    • http://ekotop.eu/userfiles/file/35974588996.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160bef8e799b49---kosoduwibikuba.pdfIn PDF document text
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/e1882192e9d69e4315199fb3e1bfea65/69310502989.pdfIn PDF document text
    • http://tjsijiqing.com/ckfinder/userfiles/files/2021/0704/52e5e25ee916b881a58e47ea5a418973.pdfIn PDF document text
    • https://jodhpurtravels.com/nbloom/fckuploads/file/7330614736.pdfIn PDF document text
    • http://viacaosaopedro.com/www/js/ckfinder/userfiles/files/jokasavojopodojof.pdfIn PDF document text
    • http://akicgiyim.com/userfiles/file/vekexajokipogedopat.pdfIn PDF document text
    • http://summithigh49.com/clients/3/33/3334069ac8a672cbece4a9536eb221cc/File/zufofonigiwifu.pdfIn PDF document text
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/6cc4bd58d47d6737fe2892df4b2a92be/fogow.pdfIn PDF document text
    • https://morethancleaningservices.com/wp-content/plugins/super-forms/uploads/php/files/1b07aaf5474b9d4fef0e4f2dbe1183a1/guwuruwis.pdfIn PDF document text
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e74de9a981---kilejoravaf.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16093d4900a8ac---fepezakugavub.pdfIn PDF document text
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/4cf3d4d6650965d528c697d8a17709d0/nutixiko.pdfIn PDF document text
    • https://forcechicago.com/wp-content/plugins/super-forms/uploads/php/files/ee213029f918a3eebaf6a72c819bb669/27695541172.pdfIn PDF document text
    • https://fobiy.net/wp-content/plugins/super-forms/uploads/php/files/8b92ef7b8e6da960bec0c5fc3bf29e0b/guwux.pdfIn PDF document text
    • https://shop-ecobati.com/medias/upload/files/91882076750.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608741caabbda---76013210062.pdfIn PDF document text
    • https://www.sehersirin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b271473785---33654468075.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16087c2b8b3c2e---sixobenexabafuvido.pdfIn PDF document text
    • https://vntdc.com/upload/fck/file/60690509654.pdfIn PDF document text
    • https://wavesmaroochydore.com/wp-content/plugins/super-forms/uploads/php/files/dl9j6j381f0d9holr6157g2grl/tatulisanatatu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=the+diary+of+janePDF link annotation
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081e6afdd4e9---18556168913.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_off0000b7b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7B2 16240 bytes
SHA-256: c963bacf1bf6bd79e8bf0d58291ea68222d0d8b39fa7edc196fcd72d9206ef69
font_01_sfnt_off0000e216.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE216 10348 bytes
SHA-256: 3566dd9d240d786b32a2ca66b753d66a750198c43303136244d8841a9ddc21d8
font_02_sfnt_off0000f951.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF951 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1