Malicious PDF — malware analysis report

Static analysis result for SHA-256 81a6600432db84c2…

MALICIOUS

PDF

31.1 KB Created: 2020-06-04 04:05:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 37d017de0224cc3c6fa009e8a317c9f8 SHA-1: 18a7481b4f7fcd10afc447075466fafe894cf832 SHA-256: 81a6600432db84c22fb7762f467a2d2d03b15470462ab93be4f3eb5d77a386bc
94 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, identified by the PDF_SEO_LINK_FARM heuristic. The document body, though heavily obfuscated, contains references to medical terms and the wkhtmltopdf tool, suggesting a lure. The primary intent appears to be directing users to a vast network of linked PDF files hosted on various domains, likely for SEO spam or to distribute further malicious content. No scripts were extracted from this sample.

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://prophetesstonya.org/uploads/1/3/1/1/131163864/131163864.html#anemia+sideroblastica+diagnostico+pdf
    • http://chefnaces.com/uploads/1/3/1/4/131437969/2045830.pdf
    • http://thenthterm.com/uploads/1/3/1/4/131407292/laxafono_labekewulezon_mukedumapinadez.pdf
    • http://projectvoicescarry.com/uploads/1/3/0/2/130272281/muzip.pdf
    • http://mail.phnompenhtattoo.com/uploads/1/3/0/6/130621457/sakesediwe.pdf
    • http://golaganda.org/uploads/1/3/0/8/130874451/moxaset.pdf
    • http://ipatio.org/uploads/1/3/0/4/130490602/xopoz.pdf
    • http://adonaicontractorsllc.com/uploads/1/3/1/6/131636890/tuwisiran.pdf
    • http://donnamalonescience.com/uploads/1/3/0/9/130969331/bb298.pdf
    • http://whitmanmerrill.net/uploads/1/3/0/7/130739396/9215022.pdf
    • http://adayinthelifeofmack.com/uploads/1/3/0/8/130814351/nesuwalibugetinosiz.pdf
    • http://loveistheevidence.com/uploads/1/3/0/5/130543240/pipobulujabezun-xogefonur-muresog.pdf
    • http://own-kc.org/uploads/1/3/0/5/130543552/julat.pdf
    • http://beradumata.org/uploads/1/3/0/9/130969722/c3ccad88837fa7.pdf
    • http://prophetesstonya.org/uploads/1/3/1/1/131163864/terms.html
    • http://prophetesstonya.org/uploads/1/3/1/1/131163864/dmca.html
    • http://prophetesstonya.org/uploads/1/3/1/1/131163864/policy.html
    • https://xesebikedu.files.wordpress.com/2020/06/45347900987.pdf
    • https://ninolukubo.files.wordpress.com/2020/06/93862444881.pdf
    • https://vorosatigeb.files.wordpress.com/2020/06/96537489472.pdf
    • https://bivuwid.files.wordpress.com/2020/06/sowogilurovijukojo.pdf
    • https://zunuxav.files.wordpress.com/2020/06/58192932930.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_off000050ec.bin
65f3c1dd6f333a507465895c692291a1d8f9ac40122718e5a6161b4b515dd5f1
pdf-font-stream PDF embedded font (sfnt) at offset 0x50EC 9460 bytes