Malicious PDF — malware analysis report

Static analysis result for SHA-256 28fbc12f9322ef3c…

MALICIOUS

PDF

53.9 KB Created: 2020-07-31 15:06:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ee94363d73e63b5ee5f6575f055b2a0f SHA-1: 2c441975603eed2f1732c2977524bc842d349f73 SHA-256: 28fbc12f9322ef3cc975e274d5136bf96b25510fd83bf233085f58e3f794fa96
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a large number of embedded links, many of which point to a link farm and a known malicious redirector. The document body, though heavily obfuscated, suggests a lure related to a 'Spanish grammar workbook pdf'. The ML classifier strongly indicated maliciousness, and the heuristics confirm the presence of malicious redirector links and a link farm.

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=spanish+grammar+workbook+pdf
    • http://files.3pinapod.com/uploads/1/3/1/6/131607010/f8711f.pdf
    • http://files.faithstjoe.com/uploads/1/3/0/9/130969656/zudowar-xijomimafexeju-lanuluzojug-lokavu.pdf
    • http://files.berkeleyspringschurchofchrist.org/uploads/1/3/0/8/130814058/2b67e641b5340.pdf
    • http://files.cfuwscbursarysociety.org/uploads/1/3/0/7/130738806/aae5824ae0d8.pdf
    • http://files.cfuwsc
    • https://cdn.shopify.com/s/files/1/0430/7052/1495/files/76436304183.pdf
    • https://cdn.shopify.com/s/files/1/0427/9848/1564/files/zawakuzewo.pdf
    • https://cdn.shopify.com/s/files/1/0433/7195/4334/files/72751766307.pdf
    • https://cdn.shopify.com/s/files/1/0427/9628/6111/files/difag.pdf
    • https://cdn.shopify.com/s/files/1/0429/9037/0975/files/14658854802.pdf
    • https://cdn.shopify.com/s/files/1/0433/5602/9093/files/bodolakonuwefotizisanimep.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/34803766861.pdf
    • https://cdn.shopify.com/s/files/1/0433/0881/0398/files/55806585115.pdf
    • https://cdn.shopify.com/s/files/1/0432/3010/1668/files/3293324563.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/50537202024.pdf
    • https://cdn.shopify.com/s/files/1/0439/8202/8958/files/tolusalapapikurido.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/30617095305.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_off000094f7.bin
2c0791f36459ca6535007d2dc2cd9413e9b6866d571d184ec42f7e09139a2484
pdf-font-stream PDF embedded font (sfnt) at offset 0x94F7 5412 bytes
font_01_sfnt_off0000a722.bin
83c3c18da738bfc9541be7e1ae786d83b10a0a9ea40b38f2cf8dad22316fba0d
pdf-font-stream PDF embedded font (sfnt) at offset 0xA722 10328 bytes