Malicious PDF — malware analysis report

Static analysis result for SHA-256 426d90d83bce71f4…

MALICIOUS

PDF

56.0 KB Created: 2020-08-14 22:51:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cb43719308df8bc39942741791acb888 SHA-1: 82527c24a96fb38abb57c6e167d723e664a48bdf SHA-256: 426d90d83bce71f41e640aa397da0a12d01e12a976a9789b32978acb3dc2307d
152 Risk Score

Malware Insights

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

The PDF contains a mass external link farm, with one link identified as a known malicious redirector. The document body text, though heavily corrupted, contains the string 'Assam university application form' and the malicious URL, suggesting a lure to trick users into downloading further malicious content. The ML classifier strongly supports the malicious verdict.

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.cc/pify?keyword=assam+university+application+form
    • http://files.isuministries.org/uploads/1/3/0/8/130814043/4403222f1bcde.pdf
    • http://files.etbengineering.com/uploads/1/3/2/6/132681586/06e28ed0ac.pdf
    • https://cdn.shopify.com/s/files/1/0432/2190/9662/files/cardiovascular_system_summary.pdf
    • https://cdn.shopify.com/s/files/1/0433/8502/8758/files/jowuzipezofugopopomidat.pdf
    • https://cdn.shopify.com/s/files/1/0438/8130/0123/files/kisozerador.pdf
    • https://cdn.shopify.com/s/files/1/0431/8714/2819/files/22220483252.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/45292738862.pdf
    • https://cdn.shopify.com/s/files/1/0435/7446/0579/files/begikexevusifenuridexosos.pdf
    • https://cdn.shopify.com/s/files/1/0432/0185/5646/files/pizikisaku.pdf
    • https://cdn.shopify.com/s/files/1/0428/2040/3356/files/foxuteguzagalodelunil.pdf
    • https://cdn.shopify.com/s/files/1/0432/0965/4434/files/24654306318.pdf
    • https://cdn.shopify.com/s/files/1/0433/9875/8557/files/85282200617.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00007f93.bin
97735b1f1385c8d79ef58e638bfb896037a32968a1fb2ffe6f7f89b2bd399c44
pdf-font-stream PDF embedded font (sfnt) at offset 0x7F93 5312 bytes
font_01_sfnt_off00009195.bin
5188c67f32b4e7f7bdfc0730b18fc0592685e9387d1e1ae3055cde3af72c6a86
pdf-font-stream PDF embedded font (sfnt) at offset 0x9195 14196 bytes
font_02_sfnt_off0000bdf2.bin
c41fc46809d2260d2d1a821cef6bb00dae560fdbad380da94a93f29d012df54e
pdf-font-stream PDF embedded font (sfnt) at offset 0xBDF2 16164 bytes