Malicious PDF — malware analysis report

Static analysis result for SHA-256 aff4a8d5c50753e3…

MALICIOUS

PDF

48.3 KB Created: 2020-08-14 11:54:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2d2f29315c31d52c5e4656a1f3c77f09 SHA-1: a897e6f33d2337b7d7d195ee22a63fd1959b7ab3 SHA-256: aff4a8d5c50753e3c5fa05b67dd6892226bc4620808742d77168caf15334d40f
152 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link, pointing to 'https://ttraff.ru/wb?keyword=multiplying%20fractions%20worksheets%20grade%207'. This URL is likely part of a link farm designed to lure users to malicious content. The document body, though heavily obfuscated, also contains this URL, reinforcing the malicious intent. The ML classifier also strongly flagged this PDF as malicious.

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=multiplying%20fractions%20worksheets%20grade%207
    • http://bawufoba.milltownmonitor.com/uploads/1/3/2/6/132682646/gezerifazowesija.pdf
    • http://sukejot.mesabimusicaltheater.com/uploads/1/3/1/3/131383483/mudaroveragiwor.pdf
    • http://jezeb.unikzhi.com/uploads/1/3/1/3/131383544/gaxijifunalivano.pdf
    • http://files.itcmillwork.com/uploads/1/3/1/4/131453329/5305425.pdf
    • https://cdn.shopify.com/s/files/1/0433/5278/5055/files/35989283590.pdf
    • https://cdn.shopify.com/s/files/1/0434/9611/2294/files/dom_javascript_cheat_sheet.pdf
    • https://cdn.shopify.com/s/files/1/0429/4203/8182/files/dowinol.pdf
    • https://cdn.shopify.com/s/files/1/0429/8647/1587/files/pimugivopi.pdf
    • https://cdn.shopify.com/s/files/1/0430/0098/7801/files/vilefezodebesuworek.pdf
    • https://cdn.shopify.com/s/files/1/0432/4173/4311/files/marcha_antalgica.pdf
    • https://cdn.shopify.com/s/files/1/0437/6556/3549/files/boland_college_bursary_forms.pdf
    • https://cdn.shopify.com/s/files/1/0440/4314/1285/files/27964333818.pdf
    • https://cdn.shopify.com/s/files/1/0428/8672/5799/files/minecrfta_forge_libaraies.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/pafinekumukomotutawewokab.pdf
    • https://cdn.shopify.com/s/files/1/0437/3354/9205/files/29494579763.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_off00007ddf.bin
cab600beb16fa50d6544aa2e31ff573ee49d9e41412ec80fda0d75a01b4cebb6
pdf-font-stream PDF embedded font (sfnt) at offset 0x7DDF 5760 bytes
font_01_sfnt_off00009198.bin
409470efb8e2196d6505b4438426603a6388eb127d01796c8e4e7bf71e63337f
pdf-font-stream PDF embedded font (sfnt) at offset 0x9198 9996 bytes