Malicious PDF — malware analysis report

Static analysis result for SHA-256 3842f7d248af6589…

MALICIOUS

PDF

40.9 KB Created: 2020-08-29 23:52:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cc078a06f70faf33fc5a5957f6a2d81e SHA-1: 02528c7c85bf1d570bcb44c2afd7f4f311447872 SHA-256: 3842f7d248af658915ec9e3d13f575175af64da56877187021704fab96419a40
152 Risk Score

Malware Insights

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

The PDF contains a link to a redirector, which is a common tactic for distributing malware or phishing pages. The document body, though malformed, contains text related to a textbook download, suggesting a lure. The presence of numerous external links, many pointing to PDF files hosted on static.usrfiles.com, indicates a link farm designed to attract traffic, likely for malicious purposes. 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/wix?keyword=sherwood+fundamentals+of+human+physiology+pdf+download
    • https://static.usrfiles.com/ugd/b8c837_a8f2906ae8a04caa8d393c15974df4cc.pdf
    • https://static.usrfiles.com/ugd/b91566_baef45807e5940679985391044181260.pdf
    • https://static.usrfiles.com/ugd/b8c837_f36935d220e1433e9046aa06795b78b8.pdf
    • https://static.usrfiles.com/ugd/ace02d_5cbe82f96d7f41ccaf676439c236ea08.pdf
    • https://static.usrfiles.com/ugd/b8c837_70961a14e05f4d12a2d9443d7faf2da3.pdf
    • https://static.usrfiles.com/ugd/b8c837_e97a4c2bb7ae48c3aba4fe4fdf46d109.pdf
    • https://static.usrfiles.com/ugd/b8c837_fe522e3589b548c8a71564471d40eba4.pdf
    • https://static.usrfiles.com/ugd/b8c837_6f843f2230d04802a9bf72260ef7aaef.pdf
    • https://static.usrfiles.com/ugd/b8c837_d41fd1c364a34d419bdf193ae9978d5f.pdf
    • https://static.usrfiles.com/ugd/b8c837_9a2a4ab32b8341d4a2172f6311bc9e59.pdf
    • https://cdn.shopify.com/s/files/1/0437/9328/5277/files/wexuj.pdf
    • https://cdn.shopify.com/s/files/1/0430/3123/2674/files/aisc_steel_construction_manual.pdf
    • https://cdn.shopify.com/s/files/1/0430/5793/8581/files/misakopudotefuzepuwujodez.pdf
    • https://cdn.shopify.com/s/files/1/0434/8579/0358/files/free_spanish_color_worksheets.pdf
    • https://cdn.shopify.com/s/files/1/0434/2808/5912/files/71870090758.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_off00006114.bin
ff4d18054849b317be0dd9ed5d5d784926462167a2e65ce96ef1c7ca22020c97
pdf-font-stream PDF embedded font (sfnt) at offset 0x6114 5752 bytes
font_01_sfnt_off00007495.bin
94a12fdfc314f2f5ec48326100e4cca06a39f09ebbae8b72d71955ab4cc886aa
pdf-font-stream PDF embedded font (sfnt) at offset 0x7495 9968 bytes