Malicious PDF — malware analysis report

Static analysis result for SHA-256 04931c41c62fdcf1…

MALICIOUS

PDF

65.2 KB Created: 2020-04-18 16:20:39 +03:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6)
MD5: 253ecd4a79e5a542fb301d421964365a SHA-1: 291c731dccdfbfe74d9e41795628e4fa02509239 SHA-256: 04931c41c62fdcf150321616f385bbf41ea0b53ba694533dd041e1b064c064c4
136 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to other PDF files with numeric slugs, indicating a potential link farm or SEO manipulation tactic. The ML classifier also flagged this PDF as malicious. While no scripts were explicitly extracted, the presence of numerous external URLs suggests an attempt to redirect the user to malicious or deceptive content, possibly as part of a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9696

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://sayulitadestinationweddings.com/uploads/1/3/0/5/130551019/130551019.html#indentured+servitude+and+slavery+packet+answers
    • http://elizabethhayesashleetaylor.com/uploads/1/3/0/5/130539838/2690521.pdf
    • http://ahbaker.com/uploads/1/3/1/6/131606125/zozokoparisakuv.pdf
    • http://bricknellbuilding.com/uploads/1/3/0/4/130483457/tufanuka.pdf
    • http://masotaconstruction.com/uploads/1/3/1/4/131408798/xikukadiruwonufejoju.pdf
    • http://phenomenalprotectivesecurityservices.com/uploads/1/3/1/3/131398272/jananisakumew_xigilan.pdf
    • https://medium
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • 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/
    • https://fedoraproject.org/wiki/Licensing/LiberationFontLicense
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b4c6.bin
a4a6b0ab84e1c29179b79b533d5a1110133557555ca0b93b954cd7d00719971b
pdf-font-stream PDF embedded font (sfnt) at offset 0xB4C6 9316 bytes
font_01_sfnt_off0000d7d0.bin
41d5c9cb4d60b7530e3cfd93a78efd430fe179aa57a8296e74fb8a971da4b0ee
pdf-font-stream PDF embedded font (sfnt) at offset 0xD7D0 2600 bytes
font_02_sfnt_off0000e0f9.bin
32b54217619f9438721b423dc2f4f4da0f78781b0811ea49af2be6b0310ecf56
pdf-font-stream PDF embedded font (sfnt) at offset 0xE0F9 16164 bytes