Malicious PDF — malware analysis report

Static analysis result for SHA-256 868cde437a3ef120…

MALICIOUS

PDF

42.8 KB Created: 2020-04-10 06:40:34 +03:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6)
MD5: 493ef11280f8fb11e7933f4da675c5c5 SHA-1: 10213dc71937203bd3361e499b9e19a79416bd41 SHA-256: 868cde437a3ef12012341c27f82fe821ffacc7b4d6d75bd6b338056260b83324
136 Risk Score

Malware Insights

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

The PDF contains a large number of external links to other PDF files hosted on various domains, indicating a link farm or a distribution mechanism for further malicious content. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous SEO-like links suggests an attempt to manipulate search results or distribute payloads. No scripts were extracted, but the structure points to a malicious document delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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.
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://weddingdjthousandoaks.com/uploads/1/3/1/4/131406535/131406535.html#calcular+matriz+inversa+con+matriz+adjunta
    • http://jsguldsmide.se/uploads/1/3/1/4/131483772/5471896.pdf
    • http://curvaceouscoutureweddingdressesma.com/uploads/1/3/0/7/130776539/580ac51b73.pdf
    • http://agendart.ca/uploads/1/3/0/5/130588870/zirimosuvumiteb_xawefisotaz_xarazananavutu.pdf
    • http://indigenousmanagement.net/uploads/1/3/0/6/130620657/xutomuwe.pdf
    • http://bipsss.com/uploads/1/3/1/3/131381243/dametezisip.pdf
    • http://scarwf.org/uploads/1/3/0/7/130775174/5c4604767.pdf
    • http://vegandsm.com/uploads/1/3/0/9/130969960/nizokulilibowulemisa.pdf
    • http://ajdevitt.com/uploads/1/3/1/1/131164157/3893755.pdf
    • http://sunlightsilverjewelry.com/uploads/1/3/0/8/130874680/4638217.pdf
    • http://inseljensislandbar.net/uploads/1/3/0/6/130622029/tizilaxukanazemeg.pdf
    • http://galadelinternet.com/uploads/1/3/0/3/130379094/dopimafumemoli.pdf
    • http://loftconversionsmiddlesbrough.com/uploads/1/3/1/4/131408546/8209068.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/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000658f.bin
d99de96c036c96af3ead74d03bc7f1b4170c2fec4a307ff51c55d18e14a06a14
pdf-font-stream PDF embedded font (sfnt) at offset 0x658F 9604 bytes
font_01_sfnt_off000088c6.bin
3e9a9dfb40a01f9f7c9c545b28ba37f1de74591f2b47bc69a9983f40f3f3ebd7
pdf-font-stream PDF embedded font (sfnt) at offset 0x88C6 16080 bytes