Malicious PDF — malware analysis report

Static analysis result for SHA-256 d9923637b9f921e3…

MALICIOUS

PDF

40.1 KB Created: 2020-08-20 03:31:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 30c2e761e16a25c00cd506367c1c5734 SHA-1: 37d542edadddc58705936fedd04d7d9a04d804dc SHA-256: d9923637b9f921e36ab5eea7291cdf9d7b8c19ca1f1d59c8f5c158967b62d9c1
152 Risk Score

Malware Insights

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

The PDF contains a link farm and a specific malicious redirector URL, indicating an attempt to direct users to harmful content. The ML classifier strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains the malicious URL and appears to be a lure for a worksheet download.

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/pify?keyword=subject+verb+agreement+worksheets+grade+7+pdf
    • http://bejeledat.friendsofstandrews.org/uploads/1/3/0/7/130775934/vowovewetupab.pdf
    • https://cdn.shopify.com/s/files/1/0432/3796/5986/files/vivalimibiko.pdf
    • https://cdn.shopify.com/s/files/1/0431/4651/0504/files/15095910676.pdf
    • https://cdn.shopify.com/s/files/1/0438/6488/3355/files/seremekisudi.pdf
    • https://cdn.shopify.com/s/files/1/0433/9243/4343/files/fafuxetu.pdf
    • https://cdn.shopify.com/s/files/1/0431/2684/9700/files/autoresponder_for_whatsapp_app.pdf
    • https://cdn.shopify.com/s/files/1/0433/4387/2153/files/gewixapopexagoz.pdf
    • https://cdn.shopify.com/s/files/1/0429/5737/3589/files/reruvidag.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/rejukimuvili.pdf
    • https://cdn.shopify.com/s/files/1/0438/6252/4069/files/88534874971.pdf
    • https://cdn.shopify.com/s/files/1/0437/6104/1559/files/gefawuxowinebapade.pdf
    • https://cdn.shopify.com/s/files/1/0437/0622/0712/files/how_to_delete_branches_in_github.pdf
    • https://cdn.shopify.com/s/files/1/0435/8592/9375/files/bible_timeline_poster.pdf
    • https://cdn.shopify.com/s/files/1/0430/4447/0938/files/winizo.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_off00005bf2.bin
63c401dcfc4c83283de4b4ff0d59dfcfd0b8466391310b6c8b988314500fb2fd
pdf-font-stream PDF embedded font (sfnt) at offset 0x5BF2 6152 bytes
font_01_sfnt_off000070dc.bin
fd0d2d25e64bc0df3fb52f375c0fccf640d2422d18a9848bb388cc815829c7be
pdf-font-stream PDF embedded font (sfnt) at offset 0x70DC 10120 bytes