Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4733c5ee8405bd5…

MALICIOUS

PDF

50.4 KB Created: 2020-04-02 09:52:17 +03:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6) First seen: 2020-09-04
MD5: 86a7f0f7564cbad00312a40d02525d7e SHA-1: c8520af43c4cafa7fb2ce071ea5d4c45413fafa8 SHA-256: c4733c5ee8405bd52b479da0fddee54f286f1285177ac2a8e98668da2140c6c0
136 Risk Score

Malware Insights

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

The PDF document contains a significant number of external links, as indicated by the PDF_SEO_LINK_FARM heuristic. The document body, though partially corrupted, contains text related to calculating variance and mentions wkhtmltopdf, suggesting it might be a generated document. The primary attack pattern involves directing users to a large number of URLs, likely for SEO spam or to host further malicious content. No scripts were extracted from this sample.

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://stealthextracts.com/uploads/1/3/0/7/130739353/130739353.html#como+calcular+la+varianza+de+datos+agrupados PDF link annotation
    • http://holisticforyou.com/uploads/1/3/0/7/130774973/dejezepakoxegew.pdfIn PDF document text
    • http://waterstonecc.com/uploads/1/3/0/5/130539843/1d8bf7020e3bb.pdfIn PDF document text
    • http://cerebroyaula.org/uploads/1/3/0/5/130546283/derinisopul-dugepigal-xejir-xewanapumufuran.pdfIn PDF document text
    • http://derrelsofdothan.com/uploads/1/3/1/4/131437357/pikufofan.pdfIn PDF document text
    • http://rootforcefitness.com/uploads/1/3/0/8/130874475/9f7cd371d61a0.pdfIn PDF document text
    • http://richardsbestbuildergeneralcontractor.com/uploads/1/3/1/3/131380175/176f6b6e6a919dc.pdfIn PDF document text
    • http://ctkyakima.com/uploads/1/3/0/5/130550844/pewavidib.pdfIn PDF document text
    • http://chrishenryforsecretaryofstate.org/uploads/1/3/1/4/131407386/detasopulugo-rizapajovesu-revosaxowoti.pdfIn PDF document text
    • http://filohomemadegreekcakes.com/uploads/1/3/0/3/130323425/zesogexixuzar.pdfIn PDF document text
    • http://mx.saint-tims.org/uploads/1/3/0/4/130435876/2483414.pdfIn PDF document text
    • http://kimkotynski.com/uploads/1/3/0/7/130776715/1265227.pdfIn PDF document text
    • http://greenmarketdfb.org/uploads/1/3/0/2/130289096/rivazasivuwafada.pdfIn PDF document text
    • http://officedesignstore.com/uploads/1/3/0/9/130969727/a7c962551ade9.pdfIn PDF document text
    • http://impactfullcoach.com/uploads/1/3/0/6/130603932/pusosexavakajax.pdfIn PDF document text
    • http://seasonofpets.com/uploads/1/3/0/6/130604767/5416176.pdfIn PDF document text
    • http://eastmainartsfestival.com/uploads/1/3/0/6/130620431/xegamamarig-xoxudajigazakeb.pdfIn PDF document text
    • http://thesilverpennyjewelry.com/uploads/1/3/0/6/130603997/b9b44fc80d75238.pdfIn PDF document text
    • http://accuratethinker.com/uploads/1/3/0/4/130493893/rejerozumibinosis.pdfIn PDF document text
    • http://allaboutbeautybydeniseypau.com/uploads/1/3/0/7/130740205/tofovetamuzer_xolujusewubez_bulalavugeduwom_nupugamixo.pdfIn PDF document text
    • http://disabilitymanagmentsolutions.ca/uploads/1/3/0/7/130739445/668325.pdfIn PDF document text
    • http://the5talentsstore.com/uploads/1/3/0/2/130270783/kikasezevutedegos.pdfIn PDF document text
    • http://khadigabeauty.com/uploads/1/3/0/3/130313228/vofiwola-natugufawa-witefil.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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
    • https://fedoraproject.org/wiki/Licensing/LiberationFontLicenseIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text
🗂 Part of campaign: bigcitystrangers.com 6 samples

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00007899.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7899 9224 bytes
SHA-256: e7e8f620f12cbf934235b552ea11abd1d096e643ca61c740ec89da702b0c7ab9
font_01_sfnt_off00009a0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9A0D 2796 bytes
SHA-256: 97a3418bd433653dafe652ac0a0841cf2f323fe672bd45d4cf3362d7102ed122
font_02_sfnt_off0000a3f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xA3F0 16100 bytes
SHA-256: 8b2af10e73b912fa3f9386a44b8d7a960302b0f96797eb9f5fff2f07da863d5f