Malicious PDF — malware analysis report

Static analysis result for SHA-256 1881ce1fd342e386…

MALICIOUS

PDF

36.6 KB Created: 2020-06-06 13:07:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 33e0c41ce7724172ae03272d2b3cb94b SHA-1: 54ce5c4df71d128cedb6bc45f0e48effe0887dfc SHA-256: 1881ce1fd342e3864b6aaa46b4f191597ba1eedff53f461117be2c7665e50ae2
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded external links, identified by the PDF_SEO_LINK_FARM heuristic. The ML classifier also strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains URLs that are consistent with the link farm heuristic. No scripts were extracted, but the sheer volume of external links suggests a malicious intent, possibly to manipulate search engine rankings or to serve as a distribution point for further malware.

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://hostmaster.alphatoro.com/uploads/1/3/1/4/131438397/131438397.html#textos+a+usar+para+as+considera%25C3%25A7%25C3%25B5es
    • http://crowned-lash.net/uploads/1/3/0/5/130589337/2820731.pdf
    • http://techitup.org/uploads/1/3/0/9/130968933/1b302c7.pdf
    • http://chezcraig.com/uploads/1/3/0/5/130551468/1557762.pdf
    • http://pawsacrosstheborder.net/uploads/1/3/0/7/130738979/dudogaze_girudivegiwifi_pavafo_pikofi.pdf
    • http://stitcheswithluv.com/uploads/1/3/0/2/130287503/4156611.pdf
    • http://2py.undesirable.us/uploads/1/3/0/8/130873945/6107617.pdf
    • http://bowelblog.com/uploads/1/3/1/8/131857304/divenuvak_pebidemixanut_simux.pdf
    • http://ajochinger.org/uploads/1/3/0/3/130312944/d16c24f40ab70d.pdf
    • http://hannahfranzen.com/uploads/1/3/0/5/130543985/nofukufiwasere_wawis.pdf
    • http://60daystohappiness.com/uploads/1/3/0/6/130603841/gaberolisiw_paxowem_mogexuxokunexi_kulumadewodud.pdf
    • http://hostmaster.alphatoro.com/uploads/1/3/1/4/131438397/terms.html
    • http://hostmaster.alphatoro.com/uploads/1/3/1/4/131438397/dmca.html
    • http://hostmaster.alphatoro.com/uploads/1/3/1/4/131438397/policy.html
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://bibimaro.files.wordpress.com/2020/06/43659715266.pdf
    • https://bevixevekev.files.wordpress.com/2020/06/59649975782.pdf
    • https://memizasapugu.files.wordpress.com/2020/06/zajuzogesabebu.pdf
    • https://gotonuxaxoxo.files.wordpress.com/2020/06/5530603455.pdf
    • https://zufiwupaned.files.wordpress.com/2020/06/buditova.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000060a4.bin
f54ff174eaea2e125d2c7a9630398af59b0f6e4161b79ec8015e9875a43faf0c
pdf-font-stream PDF embedded font (sfnt) at offset 0x60A4 11584 bytes