Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9691d382346487c…

MALICIOUS

PDF

57.4 KB Created: 2020-10-29 16:12:40 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: 0d53d9a718a8c5be5923e28f2b8df51b SHA-1: 3d16ff4a67db87b42ef94f7faafb37de4248996b SHA-256: a9691d382346487c1ed37b6428fe167ea863200023d81176fa8304efb2aa282b
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a link disguised as information about 'Stardew valley best multiplayer mods' that redirects to a known malicious URL. This URL is part of a link farm designed to host numerous PDFs, likely for SEO-based phishing or malware distribution. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://cctraff.ru/aws?keyword=stardew+valley+best+multiplayer+mods In PDF document text
    • https://gowubezu.weebly.com/uploads/1/3/4/4/134497845/nonatumudajow.pdfIn PDF document text
    • https://wepugimi.weebly.com/uploads/1/3/1/0/131070973/8746e.pdfIn PDF document text
    • https://bilewazivabo.weebly.com/uploads/1/3/2/8/132816117/5755721.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://s3.amazonaws.com/gupuso/definition_of_curriculum_by_experts.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0500/2647/9769/files/suxav.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b8c5deb1-8248-4990-8ddb-02263cf7ab02/15006262341.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/da151fa9-b344-4a10-b76e-f55029bd88d2/setugopodagokonerizeget.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0503/2683/1267/files/3053215733.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/15332c31-8051-44ca-a301-5758fc653b47/33637350837.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2de55f8c-aaaa-4e53-bb6b-5a1b3c90ee27/el_sanador_de_caballos_descargar.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/aee8d613-c182-45aa-953d-c6c483f8cb7d/21733571554.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://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00007bbc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7BBC 5376 bytes
SHA-256: a0b29459db82a964489367e1dda6269284dac2a3119209140519422ab59cffc9
font_01_sfnt_off00008e15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8E15 11260 bytes
SHA-256: ae1574dea06a6f653d0733357454425673038a9c00e232464c34d57d99a2df73
font_02_sfnt_off0000b49f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB49F 16204 bytes
SHA-256: f04fb96856fa86c99babb5bf309615b780632e07d2318923ed038a7bfd4fd4ce
font_03_sfnt_off0000c9cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9CD 4324 bytes
SHA-256: ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3