Malicious PDF — malware analysis report

Static analysis result for SHA-256 81ec9fcbdf8f6198…

MALICIOUS

PDF

87.4 KB Created: 2021-09-19 09:16:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 0cdb62c0b2a87ce3e750e05d8d71b361 SHA-1: 4c24670d5fdd1f8807884bb7508665a99dbdfc5e SHA-256: 81ec9fcbdf8f6198e2bc10353c5a072890f24a4c6cc442d47d280415d36a8e13
116 Risk Score

Malware Insights

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

The PDF contains numerous embedded URIs pointing to external websites, many of which are hosted on domains associated with compromised CMS uploads or disposable hosting. The ML classifier strongly indicates maliciousness. The primary attack pattern involves luring users to click these links, which likely leads to phishing sites or further malware downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 6

  • 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://philabc.ru/uplcv?utm_term=lester+levenson+pdf PDF link annotation
    • http://sjatupornservices.com/file_media/file_image/file/golirag.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142525a5d691---48152819019.pdfIn PDF document text
    • https://excore.hu/ckfinder/userfiles/files/31856285880.pdfIn PDF document text
    • http://xn--80aer5aza.xn--c1acndkmcarx.xn--p1ai/ckfinder/userfiles/files/lewazogonubuzuzunid.pdfIn PDF document text
    • http://dakmet.pl/upload/zidapewixafofusolugaso.pdfIn PDF document text
    • http://krallarintavugu.com/upload/file/vowikelufiba.pdfIn PDF document text
    • http://www.szphotar.com/admin/img/files/nebesifazovaxedumu.pdfIn PDF document text
    • http://ux-school.ru/files/files/97302016241.pdfIn PDF document text
    • http://linkingpeople.info/userfiles/file/xekopetefigezawutevel.pdfIn PDF document text
    • https://stomatoloska-ordinacija-rijeka.com/files/lekujopejinadujejuwe.pdfIn PDF document text
    • http://gldbirdgel.com/user_img/files/15218760833.pdfIn PDF document text
    • http://massimobertoarchitetto.com/userfiles/files/21599666474.pdfIn PDF document text
    • http://hcm-invoice.vn/hinhanh_fckeditor/file/10957406328.pdfIn PDF document text
    • http://104.156.58.56/~web2inbox/wp-content/plugins/formcraft/file-upload/server/content/files/161461c7e05da3---5568616880.pdfPDF link annotation
    • http://phuketdriveschool.com/userfiles/file/fozizakatagewerigenomutu.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16131b32aedc7b---xinowukefatizaza.pdfIn PDF document text
    • http://jjmcp.jp/userfiles/Image/file/nixunikaxeg.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613912c1da24e---doziletufazofaveg.pdfIn PDF document text
    • https://hmanagement.net/userfiles/file/26162726455.pdfIn PDF document text
    • http://abwplazaview.com/uploads/files/kulolurugo.pdfIn PDF document text
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c8ac8f0067---fatiwofele.pdfIn PDF document text
    • http://muzycznescyzoryki.pl/userfiles/file/zumubotupubebitarosaz.pdfIn PDF document text
    • http://bridgeonlaw.com/filespath/files/20210911003602.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_off0000f26c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF26C 18360 bytes
SHA-256: b85a1496095a5f906ec9542117ec852dd5be3649196d07133f5a83a98a47c490
font_01_sfnt_off00012133.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12133 10260 bytes
SHA-256: 335ad7220e16dc96162c670d7436375b23eaaf0a62643e623680fade593b59ca
font_02_sfnt_off0001386a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1386A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1