Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1b309b6fcc5c9c4…

MALICIOUS

PDF

38.5 KB Created: 2020-07-10 14:56:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-24
MD5: 0fb4146d2ffd3a0c2b5d7f3e4b534f5c SHA-1: 613950a4d89d9c8d78d2af8a1193103e54ed4c96 SHA-256: b1b309b6fcc5c9c4406293ac0a6c35d3914688d6b719de9aba0a17bb6127f6d0
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell T1204.002 Malicious Link

The PDF file contains a large number of embedded links, many of which point to external PDF files hosted on various domains. One critical heuristic identified a link to a known malicious redirector infrastructure at `https://ttraff.ru/pify?keyword=problem+solving+worksheets+pdf`. The ML classifier strongly flagged this PDF as malicious. The document body, though partially obfuscated, also contains the same suspicious URLs, reinforcing the lure to external, potentially malicious, content.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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.
  • 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://ttraff.ru/pify?keyword=problem+solving+worksheets+pdf In PDF document text
    • http://files.ptediting.com/uploads/1/3/0/9/130969235/5730592.pdfIn PDF document text
    • http://files.silverlining-press.com/uploads/1/3/0/7/130776006/bodaduruwawil.pdfIn PDF document text
    • http://files.themontessorinurseryschool.com/uploads/1/3/2/6/132695361/9eb3582dd23cde2.pdfIn PDF document text
    • http://files.heykatedewey.com/uploads/1/3/1/4/131438439/f35d1.pdfIn PDF document text
    • http://files.theroute92.com/uploads/1/3/0/8/130873973/zuguxizamuri.pdfIn PDF document text
    • http://files.theinviterace.com/uploads/1/3/2/7/132741181/pikusosawugatab.pdfIn PDF document text
    • http://files.leadfromhere.com/uploads/1/3/1/4/131438190/9979084.pdfIn PDF document text
    • http://files.paqu.org/uploads/1/3/1/8/131871894/vibofukupu_ruzererijolibij.pdfIn PDF document text
    • http://files.moshathestylist.com/uploads/1/3/1/4/131438167/317f1da7c.pdfIn PDF document text
    • http://files.thesolidrockshop.com/uploads/1/3/0/8/130813797/zaxisufibuxuxigusi.pdfIn PDF document text
    • http://files.landandtimbermgt.com/uploads/1/3/2/6/132695361/8482604.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://fesigol.files.wordpress.com/2020/07/zazido.pdfIn PDF document text
    • https://tufasurom.files.wordpress.com/2020/07/lofixuvurafimisipopiga.pdfIn PDF document text
    • https://xobajowupoda.files.wordpress.com/2020/06/57521525514.pdfIn PDF document text
    • https://sekugonizavo.files.wordpress.com/2020/07/6790985865.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/7853/2758/files/38021594103.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/581871399.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/27055139941.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000059a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x59A0 5388 bytes
SHA-256: ed013beac829a50e58da0bc675e07bcd42b0bf5e44ad9dc8937da3b65e7af52a
font_01_sfnt_off00006bd0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6BD0 9824 bytes
SHA-256: 8e7fd61c418387d78d7bdc54de3ee8f6adbe1763b2b01b5b1e210d8b50a2db2a