Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8fd8fe9420d7fc7…

MALICIOUS

PDF

82.6 KB Created: 2021-09-08 08:51:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 4771edcae2c109e59664d60f556bd3af SHA-1: 60b2f6a2e2e7d0a4cda3874ce9994a9352ac8465 SHA-256: a8fd8fe9420d7fc7cef71dede2f8b03842114aad5fa6c2e7824ec6518bb0682a
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a link farm pointing to numerous distinct hosts, many of which appear to be compromised WordPress sites. The ML classifier strongly indicated maliciousness, and the presence of multiple links to disposable hosting reinforces the likelihood of malicious intent, such as SEO manipulation or malware distribution. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://buergerforum-tirol.at/file/furovugomozozitezob.pdf In PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/160784fdac1b9f---62881829886.pdfIn PDF document text
    • http://webbyshoe.com/fckeditor/userfiles/file/4636776061.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160939fd7cf5ef---mokamutikazit.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/16097ffd50d461---21296625056.pdfIn PDF document text
    • http://vzwsportenmuziek.com/content_docs/73082053339.pdfIn PDF document text
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083dfa7a7f81---zurifufede.pdfIn PDF document text
    • http://mygotour.com/FileData/ckfinder/files/20210602_8C216C5DBC40AE05.pdfIn PDF document text
    • http://tienphat.vn/imagesflashupload/file/kuwan.pdfIn PDF document text
    • http://jrmhandling.nl/upload/file/61488240055.pdfIn PDF document text
    • https://thekolkatapackersmovers.com/ckfinder/userfiles/files/polisifanibekalujexopara.pdfIn PDF document text
    • https://dolnoslaskialarmsmogowy.pl/imgturysta/files/48036675577.pdfIn PDF document text
    • https://grandhotelushba.com/userfiles/file/1044347016.pdfIn PDF document text
    • https://sarujiovalente.com/wp-content/plugins/super-forms/uploads/php/files/h5eon10iobuukb7mhd6rcoba4b/73720481070.pdfIn PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084b5c5536fe---79497207615.pdfIn PDF document text
    • https://opescom-store.com/uploads/FCK_files/file/86497194705.pdfIn PDF document text
    • http://aaaexpressac.com/userfiles/file/10403471231.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611ee0aa5e408---pudazumilulu.pdfIn PDF document text
    • https://secolink.sk/userfiles/file/wuxaralidonoxevusafe.pdfIn PDF document text
    • http://mtlebanon62.com/clients/5/5e/5ee551a8be14a26d7d76bc5e90dd1372/File/40102881263.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=hardness+tester+pdfPDF link annotation
    • https://sharpspringwww.kinsta.cloud/wp-content/plugins/super-forms/uploads/php/files/12e5abd69a1a4743730a06d22fecbff7/69151445801.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_off0000e0b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0B6 10224 bytes
SHA-256: 78c062dee6d8f86ae3eb5b01f4719cac056275bec126b2754ea7ec2981e711dd
font_01_sfnt_off0000f7b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7B0 17612 bytes
SHA-256: bf5ec1c33fd369219757ee4d35eb1399570c24be8b1c881e33c54bba1debd3a3
font_02_sfnt_off000124ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124FF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1