Malicious PDF — malware analysis report

Static analysis result for SHA-256 21db9c9f111d6c7f…

MALICIOUS

PDF

85.2 KB Created: 2021-09-02 22:20:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 73aea0d75e027b8e0ecd4c84fdbde0b5 SHA-1: bffca8307a6feee2abac70cc94150bbad311a797 SHA-256: 21db9c9f111d6c7f01eec4202ddd50aee035bccfad343d3433e5af5c19d8aa9d
176 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites and domains that appear to be disposable hosting. This structure strongly suggests a link farm designed to lure victims to malicious content, likely for phishing or malware delivery. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://www.varisistanbul.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a2803789f2---jamazosijapixunoririv.pdf In PDF document text
    • http://sansboundaries.com/clients/f/fd/fde0d4b6b324343791c5f0705b221951/File/rajirawagepowijama.pdfIn PDF document text
    • https://comtraining.cl/userfiles/files/rovadatik.pdfIn PDF document text
    • http://anadarkogomezfamily.com/clients/7/76/76920377ef4e0cfe2c6e77079a05cbd4/File/nukubewinegugerupit.pdfIn PDF document text
    • https://ukmalayalamnews.com/userfiles/file/83294452996.pdfIn PDF document text
    • http://amirafouad.com/uploaded_files/file/8992743928.pdfIn PDF document text
    • http://kesherisrael.com/uploadEditor/files/57377148212.pdfIn PDF document text
    • http://meyergarden.com/ckfinder/userfiles/files/mojukowaviniwagedumo.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a19af5f1a5d---96956356371.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1606d36436df15---sipofoworoz.pdfIn PDF document text
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/06f043f599c6118f2c64beaf3ee8f706/67679052067.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612964487cac2---dalun.pdfIn PDF document text
    • http://short-story.ru/upload/file/89765323452.pdfIn PDF document text
    • https://hizlipin.com/calisma2/files/uploads/bukidofavanoxo.pdfIn PDF document text
    • https://cakenflowersonline.com/userfiles/file/84235021698.pdfIn PDF document text
    • https://forcechicago.com/wp-content/plugins/super-forms/uploads/php/files/2cddf97f74e1e27b19e7ead52fc24f03/51605468584.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f00e4624cad---7803203455.pdfIn PDF document text
    • http://narcisse.sk/editor_uploads/files/15136923781.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/14e10c39a26376a1ebaee42b84307d42/74629913002.pdfIn PDF document text
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/16076f1ad6efcf---toguzakosujaremunuti.pdfIn PDF document text
    • https://jxloanchien.com/style/postimage/file/savaveseg.pdfIn PDF document text
    • https://steklo-shik.ru/userfiles/file/zegedesifulopetisaluru.pdfIn PDF document text
    • http://zoop-tech.com/ckfinder/userfiles/files/kanotedozunuvowow.pdfIn PDF document text
    • http://maslatalaia.com/userfiles/file/lupalunupelebukejuforutu.pdfIn PDF document text
    • http://79.170.40.182/boothtastic.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612a6b30288d5---kelewokufofovon.pdfPDF link annotation
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/53c39211b49fc1fc3426ef8153593a88/pudimutekebarala.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=keil+uvision+5+user+manualPDF 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_off0000e863.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE863 10460 bytes
SHA-256: 829f3d385c421f2a38be4d21ca4cf22891a14036d067e985f5c94fd9455aeb76
font_01_sfnt_off00010024.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10024 17888 bytes
SHA-256: 4bae232c6226d53e190f7e2c06e5d0e724b3e32d5bf6d0aa05edb4ad2bf3c330
font_02_sfnt_off00012ed4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ED4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1