Malicious PDF — malware analysis report

Static analysis result for SHA-256 36d50a294a4e8b9a…

MALICIOUS

PDF

42.9 KB Created: 2020-08-08 22:27:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d8ec12a946c36b83d7cfa11fedda688b SHA-1: de47a428181ea18e13ca5e9810e49fdb93879316 SHA-256: 36d50a294a4e8b9a19229f7dbfe423da9c792c0ecb3716bb7e0feb90fb44da5c
152 Risk Score

Malware Insights

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

The PDF contains a link farm designed to appear as a legitimate download for "all basic formulas of maths". However, the primary link redirects to a malicious URL (https://ttraff.cc/pify?keyword=all+basic+formulas+of+maths+pdf+download), indicating a phishing or redirection attempt. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous external links supports the 'PDF_SEO_LINK_FARM' heuristic.

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=all+basic+formulas+of+maths+pdf+download
    • http://files.barbariancrossfit.com/uploads/1/3/1/8/131857304/gekobuv_rebojivod_lotud.pdf
    • http://files.alexwanforatlanta.com/uploads/1/3/1/8/131871992/gawepazaf.pdf
    • http://files.thevirginiaashpub.co.uk/uploads/1/3/0/7/130739470/832712a7.pdf
    • https://cdn.shopify.com/s/files/1/0430/2965/9797/files/19050168215.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/bekikelazipilexujewa.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/nunirisolifugonogebivaxez.pdf
    • https://cdn.shopify.com/s/files/1/0432/3124/8542/files/vanivipusuxinelogodare.pdf
    • https://cdn.shopify.com/s/files/1/0433/4993/4229/files/verulozoniv.pdf
    • https://cdn.shopify.com/s/files/1/0432/7974/5192/files/bariatric_surgery.pdf
    • https://cdn.shopify.com/s/files/1/0431/4651/0487/files/56127026202.pdf
    • https://cdn.shopify.com/s/files/1/0431/4356/1376/files/61437877939.pdf
    • https://cdn.shopify.com/s/files/1/0434/0639/3496/files/32138552028.pdf
    • https://cdn.shopify.com/s/files/1/0437/8555/2030/files/pavaxokesixaxepino.pdf
    • https://cdn.shopify.com/s/files/1/0427/9474/6023/files/meriduv.pdf
    • https://cdn.shopify.com/s/files/1/0431/0050/4217/files/31266251611.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/21533622499.pdf
    • https://cdn.shopify.com/s/files/1/0431/3009/3728/files/25595663124.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_off00005d43.bin
7830c37971e2df17d411485fa22f8127a0350e4666c0e9915bd1384030e5b689
pdf-font-stream PDF embedded font (sfnt) at offset 0x5D43 5616 bytes
font_01_sfnt_off0000703b.bin
b89c29bae13babd47211dbe77d781b4ab1070892bd7d7a0da00942e475fc46f6
pdf-font-stream PDF embedded font (sfnt) at offset 0x703B 14880 bytes