Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4d9a069f37e9c6d…

MALICIOUS

PDF

42.0 KB Created: 2020-03-10 14:19:38 +02:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6)
MD5: f2fc3e689edfa0d20c06a8bffbfdc05c SHA-1: 9c3404e00ea527d9571aa567e9ad5171ba63a96f SHA-256: b4d9a069f37e9c6d26c23fa0c375a335afb9925446a65f76c23be4dde186e3ba
94 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of external links, many of which are dynamically generated and point to other PDF files, indicating a link farm or SEO spam tactic. The document body, though partially corrupted, contains a URL related to 'how to fix umbilical hernia after pregnancy', suggesting a lure to draw users to potentially malicious content hosted on the external sites. The ML classifier strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.
  • 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://74-123-77-223.mgwnet.com/uploads/1/3/0/7/130739427/130739427.html#how+to+fix+umbilical+hernia+after+pregnancy
    • http://www.sraetales.com/uploads/1/3/0/6/130605452/wademi-wunuranebanivir.pdf
    • http://www.dallascouplesdoc.aimeetanos.com/uploads/1/3/0/6/130603928/kamejudobowesab.pdf
    • http://roperpoolcareandrepair.com/uploads/1/3/0/8/130813416/zosupel.pdf
    • http://www.18opportunities.com/uploads/1/3/0/8/130814785/4093041.pdf
    • http://alchemystejuice.com/uploads/1/3/0/8/130813524/6d20d56178.pdf
    • http://www.wimaumamatters.com/uploads/1/3/0/5/130543320/sefirixagu_fopebifis_pegekiwomasimu_xunozakemogifi.pdf
    • http://nweqf.com/uploads/1/3/0/7/130775291/danamogomutiduvib.pdf
    • http://www.radiobeats.in/uploads/1/3/0/7/130775491/batexesenoxuzu_buvuvekisusel.pdf
    • http://compassionatelivingcourse.com/uploads/1/3/0/2/130289587/4918423.pdf
    • http://sarinaart.com/uploads/1/3/0/3/130323479/34fd8e790656a0.pdf
    • http://cjenow.com/uploads/1/3/0/5/130544352/kelete.pdf
    • http://www.ungfrivillig.no/uploads/1/3/0/3/130313213/noloj.pdf
    • http://redneckfest.org/uploads/1/3/0/2/130291783/8431769.pdf
    • http://oneofamillionwomen.com/uploads/1/3/0/2/130272241/ligolileje.pdf
    • http://chuysmex.com/uploads/1/3/0/3/130313585/a76a68a2c1.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_off00007379.bin
32446fb88b6d76614a3cd0561718fc9cb4045ac6e3a05be23d0c78c8af48dfa6
pdf-font-stream PDF embedded font (sfnt) at offset 0x7379 7740 bytes
font_01_sfnt_off000091c6.bin
83459e82cebe561b9e65dda6a09953c9e35f75e5df0fa62a624e1833cc5b8086
pdf-font-stream PDF embedded font (sfnt) at offset 0x91C6 1708 bytes