Malicious PDF — malware analysis report

Static analysis result for SHA-256 137cb5fd159f8eb5…

MALICIOUS

PDF

39.8 KB Created: 2020-08-22 00:11:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 6f52d8f63bc198e2d2f7f239bf93ab02 SHA-1: 1ce6427038084525476befb952a888d8bf447be8 SHA-256: 137cb5fd159f8eb5bafeaf20ed004ac457c52e9b73427bd491eb3b2c691dbb45
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a link farm and a redirector URL, suggesting an attempt to drive traffic to malicious infrastructure. The document body, though heavily obfuscated, contains the text 'Cotton sheet sets at walmart' and the malicious URL, indicating a lure to a phishing or scam page. The ML classifier 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.com/pify?keyword=cotton+sheet+sets+at+walmart
    • http://rifowonut.lakeeriecommunications.org/uploads/1/3/2/3/132302780/lunizibetilusis.pdf
    • http://nileni.skiingisbelieving.org/uploads/1/3/1/4/131438379/f90573.pdf
    • http://movelosem.bntarms.com/uploads/1/3/0/8/130814058/fixuzivu.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0431/2370/3969/files/58920815698.pdf
    • https://cdn.shopify.com/s/files/1/0440/7784/2597/files/wosusigivuxekekenodedijus.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/kuzizurogepibisomagin.pdf
    • https://cdn.shopify.com/s/files/1/0440/0496/6565/files/vajejes.pdf
    • https://cdn.shopify.com/s/files/1/0457/0808/3356/files/cod_fishing_reports_massachusetts.pdf
    • https://cdn.shopify.com/s/files/1/0430/4610/9345/files/50048827170.pdf
    • https://cdn.shopify.com/s/files/1/0437/6789/0069/files/binary_division_examples.pdf
    • https://cdn.shopify.com/s/files/1/0434/2831/5288/files/how_to_play_mp4_on_windows.pdf
    • https://cdn.shopify.com/s/files/1/0428/3236/3687/files/jijenafalebe.pdf
    • https://cdn.shopify.com/s/files/1/0430/3886/7607/files/accountant_cv_sample.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005e22.bin
3eccdc877f47d00f91e47eb839f6d3bf492695187ae9b6e3222568c304ffc967
pdf-font-stream PDF embedded font (sfnt) at offset 0x5E22 4924 bytes
font_01_sfnt_off00006ec2.bin
1210881add13b9cf4ba2f2adde6da04ada5f8eb3912239a670c0bc9dccfa822f
pdf-font-stream PDF embedded font (sfnt) at offset 0x6EC2 10616 bytes