Malicious PDF — malware analysis report

Static analysis result for SHA-256 66321e582e7c231c…

MALICIOUS

PDF

78.5 KB Created: 2021-09-06 04:31:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: e6478fc876cf840c9a73f1b9292cf312 SHA-1: a2a731e24e1810fb8a9923a5a0cd42dbf411dab7 SHA-256: 66321e582e7c231c8368d1c5bf6548fbae715029a9149df99e23140794223ade
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many hosted on compromised CMS platforms or disposable domains, suggesting a link farm designed to redirect users to malicious content. The ML classifier strongly indicated maliciousness, and the presence of embedded URLs points towards a phishing or malware distribution attempt. No scripts were extracted, but the overall structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • 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://coretry.ru/uplcv?utm_term=materi+kuliah+biosistematika+pdf PDF link annotation
    • https://xn--z4qq44i.xn--kpry57d/upload/actfiles/51795881808.pdfIn PDF document text
    • http://impex-italia.it/userfiles/files/81959548094.pdfIn PDF document text
    • https://phunhai.net/upload/files/rotupurofezeb.pdfIn PDF document text
    • http://fanghsin.com/uploads/files/202108280127207631.pdfIn PDF document text
    • http://brighterhealthcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/sngkgss07i92umbhcsn41fcr1f/99754721993.pdfIn PDF document text
    • http://cuakeobinhduong.com/upload/files/39510828586.pdfIn PDF document text
    • https://www.medicalbi.com/ckfinder/userfiles/files/5547267018.pdfIn PDF document text
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/0u9sin1iqqt89b53gh9nlcjc8g/88361759303.pdfIn PDF document text
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a463ec6a0fd---86295503148.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/800ccd600e44445a74d5aeca25ed6eb1/wadikudomovog.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160ac7a2f281d3---dofozorigoruw.pdfIn PDF document text
    • http://evolutionchonburi.com/userfiles/files/4341385471.pdfIn PDF document text
    • https://sunwayhk.com/louis/STARKGROUP/ckfinder/userfiles/files/29381383294.pdfIn PDF document text
    • https://louvre.lv/res/wysiwyg/file/64781025552.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/9e79100c756b475a6cc4f72070ec140f/sigudatanesetoresodomot.pdfIn PDF document text
    • http://grimastone.ru/files/6699703693.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ae1691fe8f---fakixebaxodutubono.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/lomilaxotuzunaxaka.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/1606d676872bdd---nanutaxojaduzoxar.pdfIn PDF document text
    • http://guowangcable.com/d/files/pesuxagejuwavi.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080b4965ec16---93370827832.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca73053b74---vaverekixasujezokusadaz.pdfIn PDF document text
    • http://htwy.com/upload/file/12874067799.pdfIn PDF document text
    • https://vokalensemble-vocembalo.ch/userfiles/file/sarorasekarasigufetuxudaz.pdfIn PDF document text
    • http://alessandrotria.altervista.org/areap/ckfinder/userfiles/files/33351196915.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_off0000cef9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEF9 16784 bytes
SHA-256: 7d8c89bff105dcea4538a769afee855c9b98be1a63d1763b9941e1ed08f2cb21
font_01_sfnt_off0000fa6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA6B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011282.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11282 10984 bytes
SHA-256: 6df175bb4410436c41b6702b515a2fa6bb648997ba8d2ebcc328ab3c00c64830