Malicious PDF — malware analysis report

Static analysis result for SHA-256 cdb817943fa8d9d7…

MALICIOUS

PDF

41.2 KB Created: 2020-07-09 00:56:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1deaa201b686c9f4c8f6cb94bd0f5e53 SHA-1: 68dd5e537c299426fbb21f7cb9b469d6576d5d3d SHA-256: cdb817943fa8d9d76531ba76d4fc0ca67ef6b61d444a4a6e5fedd7a7f3c43594
154 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to domains associated with link farms and redirectors. The primary lure appears to be a search result for 'base64 pdf decoder online', directing users to a malicious redirector. The ML classifier strongly indicated maliciousness, and the PDF structure itself is suspicious due to duplicate object bodies.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.
  • 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://ttraff.com/wb?keyword=base64%20pdf%20decoder%20online
    • http://files.authorkimfox.com/uploads/1/3/1/3/131379612/kemunafejebos_furugamoros_vagububike_wivosoruda.pdf
    • http://files.thetlacademy.shop/uploads/1/3/1/3/131384789/dupive-madelubupazape-dezarekinoza.pdf
    • http://files.philprobstcyclist.com/uploads/1/3/0/9/130969404/nudaxox.pdf
    • http://files.cosmicbrushes.co.uk/uploads/1/3/0/7/130738806/4660277.pdf
    • http://files.futurestarsathletics.com/uploads/1/3/0/7/130775368/d2bacbeaf.pdf
    • http://files.canmorecounselling.com/uploads/1/3/1/4/131483154/netipamuropixive.pdf
    • http://files.monumentvillageoriginal.org/uploads/1/3/2/6/132681951/7039a.pdf
    • https://guzolegevaxa.files.wordpress.com/2020/07/nebuduvobumol.pdf
    • https://mirusafib.files.wordpress.com/2020/06/muguzevogivuzijufumafe.pdf
    • https://rizujofug.files.wordpress.com/2020/06/nafodalupotu.pdf
    • https://vomujonij.files.wordpress.com/2020/07/zajalare.pdf
    • https://sudumol.files.wordpress.com/2020/07/37205639363.pdf
    • https://gopamewub.files.wordpress.com/2020/07/wuwaxolibilofesim.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/dusegu.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/rasebiv.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/13977314479.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/90442425312.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/jokopewizemaw.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000632a.bin
5522a87263835f5c0cd7bec9070331173c6a222baf29f610db16a0509bd971b7
pdf-font-stream PDF embedded font (sfnt) at offset 0x632A 5148 bytes
font_01_sfnt_off000074a8.bin
c02006fb1bdc3034fd233c54a40ed85d35ca1fe489614fb02de58c26fc1e66c7
pdf-font-stream PDF embedded font (sfnt) at offset 0x74A8 10400 bytes