Malicious PDF — malware analysis report

Static analysis result for SHA-256 dd53cbbdf15c099b…

MALICIOUS

PDF

74.6 KB Created: 2021-05-26 06:58:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 993b0615e207babfd5d5ac01355f3534 SHA-1: d7931571cfccd8d82ac24557c53bf2c47c2bbd61 SHA-256: dd53cbbdf15c099bc7a6932327a9d53f0504b5c4f5f02e46451e898c56da073c
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The PDF contains a link farm with numerous URLs pointing to other PDF files hosted on compromised WordPress sites. This structure suggests a tactic to distribute further malicious content or phish for credentials. The ML classifier strongly indicated maliciousness, and the link farm heuristic confirms a suspicious pattern of hosting multiple files on potentially compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0437824563---rorebene.pdf In PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/388j6lqumlmd6etacai2ngreqt/12406045471.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087766b96e20---59880883747.pdfIn PDF document text
    • https://actorconseil.com/files/file/votakeboxogaxatuzo.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/16075106831d20---26759721527.pdfIn PDF document text
    • http://buildinggodskingdom.com/webcms/file/71189441469.pdfIn PDF document text
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/2d0397811ef1904899206086abe92049/fipidozolesuxizizu.pdfIn PDF document text
    • http://africa-emergence2019.com/userfiles/file/datigurubokevaku.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/160acb2341a83b---53697150351.pdfIn PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abfab00606b---sutizosozuranafo.pdfIn PDF document text
    • https://irisapp.cn/uploadfiles/fckeditor/20210517/file/16212143725738.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d085449673---49567646146.pdfIn PDF document text
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/nd30n4gmpvgh21gfvr5hclu8jh/giluk.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607e3aab140bf---10972828366.pdfIn PDF document text
    • https://elpmarketing.ca/wp-content/plugins/super-forms/uploads/php/files/9d4fd8528af485d758bfce40d4eebbc0/xujoxubadizuz.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/16095116d6efa2---xifeganemotegezibenik.pdfIn PDF document text
    • https://sharidendesignasphalt.com/wp-content/plugins/super-forms/uploads/php/files/7ce7561216de5e97234b1b90e0b1781d/buxupivugejumoxabowifun.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=is+should+a+modal+verbs+of+possibilityPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e730.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE730 5520 bytes
SHA-256: c05e3d5a5c74f684852b78b78975de518832139956358ec8aa08d3ca2fa42634
font_01_sfnt_off0000f9cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9CD 10272 bytes
SHA-256: e86ce947d089aa30b87e9d5131cadef6f37954fd1d6528f320d82b2321da64ac