Malicious PDF — malware analysis report

Static analysis result for SHA-256 a2fc1c83d3fb8ea6…

MALICIOUS

PDF

35.9 KB Created: 2020-06-11 23:21:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: dc550f0b80a9030ea98be15f4873b91f SHA-1: 95a66be63243dd2f22f301d34541b5a4f0654d0d SHA-256: a2fc1c83d3fb8ea68bd3f9a2e15f32235f1c140005b6c8667cc4c63020b3c4fa
94 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a large number of external links, identified by the PDF_SEO_LINK_FARM heuristic, pointing to various domains. The ML classifier also strongly indicated maliciousness. The document body, though heavily obfuscated, contains URLs that are consistent with a link farm or SEO spamming operation, potentially used to distribute further malicious content or manipulate search engine results. The primary attack pattern involves luring users to click on these numerous external links.

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://n9.undesirable.us/uploads/1/3/1/6/131637171/131637171.html#static+induction+thyristor+pdf
    • http://healingcrystalwirewrapping.com/uploads/1/3/0/2/130291434/jevabugixoti.pdf
    • http://mikaelatrull.com/uploads/1/3/0/5/130542781/safuxebilusizo.pdf
    • http://jtgenterprises.org/uploads/1/3/0/2/130287973/fezawawoxobavevo.pdf
    • http://recoveryatsanantonio.com/uploads/1/3/1/1/131163638/gipidoronoj.pdf
    • http://el009.elrepco.com/uploads/1/3/1/0/131071114/8640425.pdf
    • http://uvcoatingsstlouis.com/uploads/1/3/1/4/131407763/wipapugotuf.pdf
    • http://truerink.com/uploads/1/3/0/9/130969346/sipaniju.pdf
    • http://juneausquared.com/uploads/1/3/0/5/130589281/405458.pdf
    • http://minnesotalodging.org/uploads/1/3/0/4/130489523/vifumomumiruvad_neduxumegir_bopimivilator_ruvekezunesi.pdf
    • https://pixudefixig.files.wordpress.com/2020/06/80849121952.pdf
    • https://vedasigup344424862.files.wordpress.com/2020/06/famunenarezunoxuk.pdf
    • https://fobizuwaj.files.wordpress.com/2020/06/potegifinebimudokanu.pdf
    • https://lufomewirumi.files.wordpress.com/2020/06/noratetuwiv.pdf
    • https://kulowufobe.files.wordpress.com/2020/06/waxumuxug.pdf
    • https://jukavazak949774331.files.wordpress.com/2020/06/xegiwibuwo.pdf
    • https://maturixox.files.wordpress.com/2020/06/rifinuvonem.pdf
    • https://xozigun417683795.files.wordpress.com/2020/06/wimefilotuxefasina.pdf
    • https://sidenugokuti.files.wordpress.com/2020/06/70106269896.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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005f8b.bin
15415df73eb75bf915d24b51649ed2696b2344d8da27b38f533ed3605d1446c6
pdf-font-stream PDF embedded font (sfnt) at offset 0x5F8B 10584 bytes