Malicious PDF — malware analysis report

Static analysis result for SHA-256 065152544b0dcf96…

MALICIOUS

PDF

43.2 KB Created: 2020-07-07 01:05:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 787789e4163385967e52532cefef411e SHA-1: bd4052fa8ab8762ae14556cb8b497902af7796a0 SHA-256: 065152544b0dcf9628093cf7590481a3ab8bd99184be90febb3cd142964de236
136 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to algorithmically generated PDF filenames on various domains. This suggests a link farm or SEO poisoning technique designed to redirect users to potentially malicious content. The ML classifier also strongly indicated maliciousness, and the presence of embedded URLs further supports this. The document body itself is largely obfuscated but contains references to the linked content.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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.
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://files.barnetselfstorage.net/uploads/1/3/0/7/130775805/130775805.html#the+atlantic+slave+trade+a+census+pdf
    • http://files.tidyplaces.com/uploads/1/3/0/9/130969760/2137293.pdf
    • http://skilledinsight.com/uploads/1/3/2/6/132681157/jelawar.pdf
    • http://corevolutionart.com/uploads/1/3/0/9/130969206/5402010.pdf
    • http://centralcoastautoandmarinedetailing.com.au/uploads/1/3/1/1/131164531/sawevinamoxar-luronamevedaxe-pigigivotudimu.pdf
    • http://innovacionpublicitariamagenta.com/uploads/1/3/1/4/131438362/xinaxa.pdf
    • http://assortedartistries.net/uploads/1/3/0/7/130740205/gitoviv.pdf
    • http://files.crystalblueocean.com/uploads/1/3/1/3/131398509/bufazab-lanew-sisadijinono.pdf
    • http://gertisglutenfreedom.com/uploads/1/3/0/4/130483863/4360240.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://giwogixud.files.wordpress.com/2020/06/136074807.pdf
    • https://tegekaxinup.files.wordpress.com/2020/07/77557402775.pdf
    • https://vewulox.files.wordpress.com/2020/07/kubiwezuropo.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000068aa.bin
ec3378e48974218d36c05b57395ea798d4192c7202ffc6a1b48e3f175fcece3d
pdf-font-stream PDF embedded font (sfnt) at offset 0x68AA 5024 bytes
font_01_sfnt_off000079b4.bin
dc35e2c780dd7e1d94f11f63ecc73b6320abbca0291ce10d529d982a720a1232
pdf-font-stream PDF embedded font (sfnt) at offset 0x79B4 11800 bytes