Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd3fd8b9eaa23f28…

MALICIOUS

PDF

42.1 KB Created: 2020-09-01 14:51:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 15f6f8e62b67e1bde8fa9c2d78dc8e6e SHA-1: 693b3b823ae4cc241626593712cdaf0786b0fd42 SHA-256: cd3fd8b9eaa23f28f38ecb0ba92e6a16216d1798bfce905418ca24828b507fb9
152 Risk Score

Malware Insights

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

The PDF file was identified as malicious due to a critical heuristic firing for a redirector link pointing to known malicious infrastructure. It also contains a large number of external PDF links, characteristic of a link farm. The primary malicious IOC is the redirector URL, which is likely used to funnel users to a compromised or malicious site. No scripts were extracted from this sample.

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.ru/wix?keyword=fusiform+aneurysm+ascending+aorta
    • https://static.usrfiles.com/ugd/b8c837_f9094cecce29413e8dbf969416a669a0.pdf
    • https://static.usrfiles.com/ugd/a2d007_5cc23ac172af4fd09d74b2fcdca1d22e.pdf
    • https://static.usrfiles.com/ugd/b8c837_06f3629ff1844fcb9a9f43b560af8846.pdf
    • https://static.usrfiles.com/ugd/23b571_95819d0029f74fe7b97f644e8ba47764.pdf
    • https://static.usrfiles.com/ugd/b8c837_353b0119927641cb82803edbdeb8fc6f.pdf
    • https://cdn.shopify.com/s/files/1/0432/1850/1799/files/41315084233.pdf
    • https://cdn.shopify.com/s/files/1/0434/2562/8327/files/29928020642.pdf
    • https://static.usrfiles.com/ugd/e643da_40b82a1eb86248ef843895ff38e0d34c.pdf
    • https://static.usrfiles.com/ugd/73c254_5d31cde054fc466199c2c4b8890567ae.pdf
    • https://static.usrfiles.com/ugd/b8c837_6040b59e78994197999565aa9c536a0d.pdf
    • https://static.usrfiles.com/ugd/b8c837_2980f03b62a040bf9d78b0240be816ca.pdf
    • https://cdn.shopify.com/s/files/1/0432/1656/8487/files/wewemokolimosirelikuw.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/1402562920.pdf
    • https://cdn.shopify.com/s/files/1/0434/4768/1191/files/73226685449.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_off00006686.bin
962130cd22cf38b5c7a568431da32703c0a4b98c9ba3f1e6d6942f8614ee4285
pdf-font-stream PDF embedded font (sfnt) at offset 0x6686 5364 bytes
font_01_sfnt_off000078bb.bin
c878c816f2bdb4a31bd8e10947a77e50e744669173f53340f0e5984e2b37056e
pdf-font-stream PDF embedded font (sfnt) at offset 0x78BB 10152 bytes