Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b5cf88171f699d7…

MALICIOUS

PDF

29.7 KB Created: 2018-06-11 08:43:12 -04:00 Authoring application: wkhtmltopdf 0.12.4 (via Qt 4.8.7) First seen: 2020-08-10
MD5: 2144464c5f6f455137950b4326c4bb68 SHA-1: 748c3ec0ffa6e084cbaaca9e44941ce870c684e3 SHA-256: 4b5cf88171f699d767548c22f0dd5ea52a65047a50008532d9b8a419539f7f12
130 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File

The PDF contains a heuristic firing for an external URI pointing to a suspicious domain, which is likely intended to trick the user into downloading a file. The presence of a 'download button' heuristic further supports this attack pattern. The ML classifier also flagged the document as malicious. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9525

Heuristics 4

  • Fake 'free download' SEO-poisoning PDF critical PDF_SEO_FAKE_DOWNLOAD
    The ML classifier flagged this PDF AND it carries a visual download/call-to-action lure AND an off-domain server-side download-gateway link whose query string names a document payload. This three-signal conjunction is the fake-document / 'free PDF download' SEO-poisoning delivery pattern: the page is padded with benign decoy links to dilute classifier scores while funnelling the victim through the gateway to malware/scareware. Acting only on the conjunction keeps benign download-bearing PDFs from being misflagged.
  • PDF carries a PHP-gateway SEO-spam PDF link farm medium PDF_SEO_PHP_GATEWAY_LINK_FARM
    PDF contains four or more clickable links whose target is a `.php` gateway with a multi-word search-PHRASE document slug embedded after it (e.g. 'index.php?.../binary+options+trading+nz.pdf' or 'pdf.php/cialis-dosage-side-effects.pdf'). Legitimate PHP-served documents use a filename or numeric id, not a search-query phrase, so this is the generated SEO link-farm shape — pharma / binary-options / 'free download' spam that ranks for queries and routes users into payload/redirect chains. The PDF itself carries no exploit — the risk is the linked destinations.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://uncpbisdegree.com/download3.php?q=shakedown-jack-davis-thrillers-book-1.pdf In PDF document text
    • http://uncpbisdegree.com/download4.php?q=shakedown-jack-davis-thrillers-book-1.pdfIn PDF document text
    • http://oceanviewpub.com/about-us/In PDF document text
    • http://baltimoresounds.com/list.htmlIn PDF document text
    • http://doowopshoobop.com/teen.htmlIn PDF document text
    • http://www.flipmall.com/jukebox3.htmIn PDF document text
    • http://www.78rpm.co.uk/tva.htmIn PDF document text
    • http://www.tutto-italia.com/tabcs.htmIn PDF document text
    • http://uncpbisdegree.com/1/solution-manual-for-personal-financial-planning.pdfIn PDF document text
    • http://uncpbisdegree.com/1/solutions-manual-pearson-computer-science.pdfIn PDF document text
    • http://riverside-resort.net/1/welcome-to-springboard-english-textual-power.pdfIn PDF document text
    • http://uncpbisdegree.com/1/the-final-detail-a-myron-bolitar-novel.pdfIn PDF document text
    • http://uncpbisdegree.com/1/succeed-management-solutions-jobs.pdfIn PDF document text
    • http://riverside-resort.net/1/usps-track-confirm-postal-service-usps-tracking-il.pdfIn PDF document text
    • http://uncpbisdegree.com/1/the-concise-sage-handbook-of-islamic-studies.pdfIn PDF document text
    • http://uncpbisdegree.com/1/the-billionaires-new-assistant-dominators-1-georgina-sand.pdfIn PDF document text
    • http://uncpbisdegree.com/1/shiv-crew-rune-alexander-1-laken-cane.pdfIn PDF document text
    • http://uncpbisdegree.com/1/stability-theory-of-elastic-rods.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://www.onelook.com/pm/In PDF document text
    • https://y.qq.com/In PDF document text
    • http://www.microsofttranslator.com/bv.aspx?ref=SERP&br=ro&mkt=en-US&dl=en&lp=ZH-CHS_EN&a=https%3a%2f%2fy.qq.com%2fIn PDF document text
    • http://music.163.com/In PDF document text
    • http://www.microsofttranslator.com/bv.aspx?ref=SERP&br=ro&mkt=en-US&dl=en&lp=ZH-CHS_EN&a=http%3a%2f%2fmusic.163.com%2fIn PDF document text
    • http://www.dictionary.com/e/s/word-of-the-year-list/In PDF document text
    • http://go.microsoft.com/fwlink/?LinkId=521839&CLCID=0409In PDF document text
    • http://go.microsoft.com/fwlink/?LinkID=246338&CLCID=0409In PDF document text
    • https://go.microsoft.com/fwlink/?linkid=868922In PDF document text
    • http://go.microsoft.com/fwlink/?LinkID=286759&CLCID=409In PDF document text
    • http://go.microsoft.com/fwlink/?LinkID=617297In PDF document text
    • https://fedoraproject.org/wiki/Licensing/LiberationFontLicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00003afc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x3AFC 9796 bytes
SHA-256: 595ad4235abc374f8bdd8539f7e909787baf7de49ff05630f63c1ebf8025121b
font_01_sfnt_off00005a46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x5A46 7136 bytes
SHA-256: f8ed34efc81f3d4d0f1c804dbd18fbda25b8a73f17cbb2382b3d14735b3adac6