Malicious PDF — malware analysis report

Static analysis result for SHA-256 57b1a2c3f68a1857…

MALICIOUS

PDF

151.2 KB Created: 2021-04-18 19:31:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: a023f43389236b293e06969423c9ccdf SHA-1: 492f95c6b9894b213b9d9d67d4d0812e49a92780 SHA-256: 57b1a2c3f68a185776b44671a0af7b6e673c95849964c1a4e4000f37b87d9fc5
126 Risk Score

Malware Insights

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

The PDF document contains numerous embedded URLs, with the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicating a link farm structure. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or redirecting users to malicious sites. Although no scripts were explicitly extracted, the PDF structure itself is used to host and present these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/80982398497.pdf In PDF document text
    • https://www.jwico.com/sites/default/files/webform/vuvosiritixulufanili.pdfIn PDF document text
    • http://spotlight-sites.com/sites/default/files/webform/sizewavajifur.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/ziseriwutekezarog.pdfIn PDF document text
    • https://www.newburghgroup.com/sites/default/files/webform/resumes/falaburisidibiwad.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/32675510575.pdfIn PDF document text
    • https://www.woonsocketri.org/system/temporary/webform/viwubamonutimujogigifowi.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=singer+2018+rankingPDF link annotation
    • https://thesanfordschool.asu.edu/sites/default/files/webform/87767597376.pdfIn PDF document text
    • https://campusrec.princeton.edu/system/files/webform/wawojamifot.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/xafuzekimizitigemuseli.pdfIn PDF document text
    • https://umatter.princeton.edu/system/files/webform/requests/72435273025.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/26360011081.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/posilo.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_002_off0001395b.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x1395B 69392 bytes
SHA-256: 57ab1076030893755a1730e1ee2f83ef2cdbebe319171ccad8ac95e86329c40f
font_01_sfnt_off000208da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x208DA 4928 bytes
SHA-256: 405b08b1b7bf42eef2d4d269c13b38d7e546fee4c81e5c9469ab868c1b3cbeb4
font_02_sfnt_off00021993.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x21993 12408 bytes
SHA-256: 0428a382aa336990cea3b304ad854293da24f2fbffb09f5e96f2fabd26802e9f
font_03_sfnt_off00024197.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x24197 4324 bytes
SHA-256: 1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e

Open this report in the interactive analyzer, or submit your own file for analysis.