Malicious PDF — malware analysis report

Static analysis result for SHA-256 39c81d3bfb9466f8…

MALICIOUS

PDF

41.6 KB Created: 2020-03-29 23:00:08 +03:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6)
MD5: eb6a26c38e90a442485cec695e36de7b SHA-1: 080dfc0f47dccfcab33590a063c5dff5bbbc2399 SHA-256: 39c81d3bfb9466f8823a24670ae3a9bad8752b4bec55033a67ff9192d2a3ecdc
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded external links, a technique often used for SEO spam or to redirect users to malicious sites. The ML classifier strongly indicated maliciousness, and the PDF_SEO_LINK_FARM heuristic confirms the presence of a link farm. The document body itself is heavily obfuscated but contains references to the URLs, suggesting a deliberate attempt to drive traffic to these external resources.

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://occasionsbygigi.com.au/uploads/1/3/1/3/131382590/131382590.html#concepto+de+%C3%A1ngulo+llano+ejemplo
    • http://sunrisehomebaking.com/uploads/1/3/0/5/130543059/wimosowoxivoput.pdf
    • http://clinicalatinoamericanatelge.com/uploads/1/3/0/7/130739140/zisemedumuzixap.pdf
    • http://mail.ladavisbooksllc.com/uploads/1/3/1/0/131070598/6889467.pdf
    • http://theelaynawilliams.com/uploads/1/3/0/3/130323491/1285786.pdf
    • http://slothsu.com/uploads/1/3/0/8/130814178/mapusolidapiz.pdf
    • http://buildupallestimenti.com/uploads/1/3/1/3/131379375/sejifewu_sikogud_jabonefug_gataramu.pdf
    • http://greaterlifefinancial.com/uploads/1/3/1/3/131379324/vixijeguxuzafig.pdf
    • http://caterers.solutions/uploads/1/3/0/2/130287281/1b3201b1fd1.pdf
    • http://counselingcollaborativesllc.com/uploads/1/3/0/6/130620367/jawinigewakejujojiz.pdf
    • http://blanchardandassociatesllc.com/uploads/1/3/0/4/130478484/pegarizuvab_wikudij_deraxaduvixige_renamekok.pdf
    • http://birthingwithstephanie.com/uploads/1/3/0/6/130604585/zuvofuzere.pdf
    • http://luckywin-autoparts.com/uploads/1/3/0/6/130621552/5c31f59bd238.pdf
    • http://mogadoresystems.com/uploads/1/3/1/0/131070619/ea56665156.pdf
    • http://southpacificsuperyachtclub.com/uploads/1/3/0/5/130539131/956e883719ec4.pdf
    • http://clarionchristianschool.com/uploads/1/3/0/2/130289779/xutiragu.pdf
    • http://taossnowboardvalley.com/uploads/1/3/0/2/130289731/nojuxozojas.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_off00006c0e.bin
9b6a3f4c7d9e9504e04ab5370c6ff6fc621b8a714afa7b9e7dfc601f44b55924
pdf-font-stream PDF embedded font (sfnt) at offset 0x6C0E 8216 bytes
font_01_sfnt_off00008a2c.bin
5dc0376f1ea922fdf15aeafd68d89cdb996e38f08f5fdbfb89e696d47db0d895
pdf-font-stream PDF embedded font (sfnt) at offset 0x8A2C 3580 bytes