Malicious PDF — malware analysis report

Static analysis result for SHA-256 77a1961999ada4d7…

MALICIOUS

PDF

81.8 KB Created: 2021-09-02 01:36:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 68a1ffc19a58a9c07bd11fff1890ae07 SHA-1: 96bd7a5ab638a909ff30daf074e7e7444c33d635 SHA-256: 77a1961999ada4d781eb4bf06cf38e2facbf6d5aae11409c0f29c42be18eb3b3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with multiple URLs pointing to compromised WordPress upload directories. The document body is heavily obfuscated and unreadable, suggesting it is designed to hide its true purpose, which is likely to redirect users to malicious sites for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/ebe169bc7b80b383e5e31bdafd80dd80/84480633039.pdf In PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/1htsb80l75lggvu4ppb6d5707a/wenobusulamixaz.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/8bb23ee5fc7d61c72caf55f7cca371c2/807195618.pdfIn PDF document text
    • http://cleanyachts.it/writable/public/userfiles/file/votamonolajepago.pdfIn PDF document text
    • http://sochi-vitrazhi.ru/ckfinder/userfiles/files/fokitufitig.pdfIn PDF document text
    • https://rlvanstory.com/wp-content/plugins/super-forms/uploads/php/files/4437bc678003a2c2e39cbd7b3acf2a72/46075697440.pdfIn PDF document text
    • http://shinex-auto.com/userfiles/file/guwejidizomosejubum.pdfIn PDF document text
    • http://zjhywt.com/images/upload/File/zukalip.pdfIn PDF document text
    • http://stlnsk.ru/uploads/file/66534650909.pdfIn PDF document text
    • http://namngonviet.vn/user-/files/15792556121.pdfIn PDF document text
    • http://americasbestmanassas.com/uploads/files/37234376835.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/81faaa8402404d1cd37943fc31a4c694/18581341499.pdfIn PDF document text
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/7b01f87a74a245eb1db76e3c5bad4e6f/2653768308.pdfIn PDF document text
    • https://arvikabc.com/images/uploadedimages/file/84863486252.pdfIn PDF document text
    • http://abwingscolley.com/uploads/files/88688112761.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606d49a2acd5b---5977762301.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085cdabe7856---31438239809.pdfIn PDF document text
    • https://matrainagycsalados.hu/userfiles/file/42407245504.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/16086707b08ab4---nefebugeze.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/2c1d5b84e02726e6be4f04292045b168/13718673194.pdfIn PDF document text
    • https://jodhpurtravels.com/nbloom/fckuploads/file/lubojupudekofuxo.pdfIn PDF document text
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/887cc77406d1283e979569fa5ca7bc62/66522524291.pdfIn PDF document text
    • http://russkiivopros.com/images/FCKeditor/file/23205739333.pdfIn PDF document text
    • https://roweryelectra.eu/app/webroot/uploads/file/16270744528776.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f4d84f32ee---fuzas.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=he+touched+me+hymnPDF 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://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_off0000dad8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAD8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f2ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2EF 10272 bytes
SHA-256: dd640257c8534d288b82bd94f5e4f405c6b5b8ab2a96bbed45de3c10040f99a2
font_02_sfnt_off000109d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109D3 18048 bytes
SHA-256: 3f5fe4902567e04b737b0c8ea08fa899134af0de33baacd56482f1d7b70a32dd