Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b012c52373b4207…

MALICIOUS

PDF

44.0 KB Created: 2020-07-09 17:51:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e4df207481fe1216c42d08eea13ea2f1 SHA-1: 485987c717a9cc8cb0df081dc41f19d3b99a8af5 SHA-256: 2b012c52373b4207497c865a84bb656d06a37035c9fa548be00ca667b28df0e3
154 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to external PDF files hosted on various domains, suggesting a link farm or SEO poisoning attempt. One critical heuristic firing indicates a direct redirect to a known malicious URL, 'https://ttraff.ru/wb?keyword=classroom%20phrases%20for%20students%20pdf', which is the primary indicator of malicious intent. The document body, though partially corrupted, contains text related to 'classroom phrases' and the PDF creation tool, likely serving as a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.
  • 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/wb?keyword=classroom%20phrases%20for%20students%20pdf
    • http://files.mrshanksclass.com/uploads/1/3/0/9/130969987/zuban.pdf
    • http://files.jamesgoldgeier.com/uploads/1/3/2/3/132302966/ribeso-zagemokelu.pdf
    • http://files.kocanada-usa.com/uploads/1/3/1/4/131437538/zorodoke.pdf
    • http://files.heavencanbefound.com/uploads/1/3/1/3/131384018/tizalunovemili.pdf
    • http://files.theearnestoptimist.com/uploads/1/3/1/8/131871954/fac4d7.pdf
    • http://files.gotnlc.com/uploads/1/3/1/4/131454306/fogiz.pdf
    • http://files.madebyloulou.net/uploads/1/3/1/8/131871891/59bfb6ba928ffb6.pdf
    • http://files.rosebudpreschool.org/uploads/1/3/2/8/132815960/c2e6ffd9277c.pdf
    • https://kanagop.files.wordpress.com/2020/06/97006527957.pdf
    • https://dojobavoviz.files.wordpress.com/2020/06/kumujapomokemo.pdf
    • https://toposimijiv.files.wordpress.com/2020/06/45537406353.pdf
    • https://nenusanej.files.wordpress.com/2020/06/nusagosivuzuvojusutix.pdf
    • https://zusuxomo.files.wordpress.com/2020/06/nerej.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/87913440599.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/25322908130.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/dedepisolutiri.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/jedajuzosefowi.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/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006d73.bin
6c51e5ea0d723b7620c9487e312d17e71b5d342d37f4718fc960f1cff3930868
pdf-font-stream PDF embedded font (sfnt) at offset 0x6D73 5136 bytes
font_01_sfnt_off00007ec2.bin
a5fa05fbff8f6a2357b016b7394bd68c84ed4cf5eff8a8ff3ea651c35b96690c
pdf-font-stream PDF embedded font (sfnt) at offset 0x7EC2 10656 bytes