Malicious PDF — malware analysis report

Static analysis result for SHA-256 611c0a92d0a54181…

MALICIOUS

PDF

41.3 KB Created: 2020-08-12 12:52:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2325b2ce03bab547836ff0a27f77d026 SHA-1: 503533d89638fc29700980fd9bf16c1978638134 SHA-256: 611c0a92d0a54181da175ac070a7a2f8757e72d993e4dd9d877e2e777f63a561
154 Risk Score

Malware Insights

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

The PDF contains a link to a redirector, which is a common tactic for distributing malicious content. The document body, though heavily obfuscated, contains the same URL and a large number of links to other PDFs, suggesting a link farm designed to attract traffic. The ML classifier also strongly indicated maliciousness.

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/wb?keyword=identifying%20asymptotes%20worksheet
    • http://files.thegorsebush.com/uploads/1/3/0/7/130775520/e23b9573f.pdf
    • http://bumederi.keeptalkingspeech.com/uploads/1/3/1/4/131453194/xegop.pdf
    • http://files.freedomfromcancerchallenge.org/uploads/1/3/1/6/131636789/fc4a35f826850.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0435/3448/3616/files/revaxitomosovadi.pdf
    • https://cdn.shopify.com/s/files/1/0430/9614/6074/files/escala_bristol_heces.pdf
    • https://cdn.shopify.com/s/files/1/0431/8212/9320/files/6851259399.pdf
    • https://cdn.shopify.com/s/files/1/0436/0405/0084/files/sogagir.pdf
    • https://cdn.shopify.com/s/files/1/0434/0023/3112/files/53606897772.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/40133843423.pdf
    • https://cdn.shopify.com/s/files/1/0449/7958/5192/files/xurutenurowozimaxitamu.pdf
    • https://cdn.shopify.com/s/files/1/0432/4442/1282/files/74069840092.pdf
    • https://cdn.shopify.com/s/files/1/0429/2290/1663/files/split_to_single_jpg.pdf
    • https://cdn.shopify.com/s/files/1/0430/6088/7705/files/35937112697.pdf
    • https://cdn.shopify.com/s/files/1/0447/8432/0661/files/mumadurixubuzo.pdf
    • https://cdn.shopify.com/s/files/1/0432/8210/4478/files/lolidinujemogudezusot.pdf
    • https://cdn.shopify.com/s/files/1/0428/4999/2860/files/65387124374.pdf
    • https://cdn.shopify.com/s/files/1/0432/3491/8568/files/56690932758.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_off0000621f.bin
fbbafa0261986e1f43a15da78f8ab00834949e8ac087d35b2061d158cdd04512
pdf-font-stream PDF embedded font (sfnt) at offset 0x621F 5620 bytes
font_01_sfnt_off0000752c.bin
f4a0e67f083e48b6d85898666567f5c866f7804a4d9afaabf4b30a3681a77b1f
pdf-font-stream PDF embedded font (sfnt) at offset 0x752C 10124 bytes