Malicious PDF — malware analysis report

Static analysis result for SHA-256 c307b51fd6b4eb7a…

MALICIOUS

PDF

40.3 KB Created: 2020-08-31 23:24:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c4b5da5e4834a013f6e3750721b56f2b SHA-1: 2417c1d5907401413d705c214cc3d12701d9b1ee SHA-256: c307b51fd6b4eb7afc2ce9c7aa249cda01f35849ae4bfa9ec8e741d15ea8e342
152 Risk Score

Malware Insights

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

The PDF contains a mass of external links, many pointing to a link farm hosted on static.usrfiles.com, and one critical link to a known malicious redirector at ttraff.cc. The document body, though heavily obfuscated, contains the target URL and appears to be a lure related to academic content. The ML classifier strongly indicates 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/wix?keyword=centre+tapped+full+wave+rectifier+pdf
    • https://static.usrfiles.com/ugd/4b874d_00e115f2c35a48ccbb03d5dfd74ccdaf.pdf
    • https://static.usrfiles.com/ugd/3be3a7_e32abece2bd244f7801a133bf43a6ee1.pdf
    • https://static.usrfiles.com/ugd/b8c837_d2a9a602e43c4a968887a957642c7d41.pdf
    • https://static.usrfiles.com/ugd/1a89c8_5edf9d2e118d4e5f956dbbadb62509af.pdf
    • https://static.usrfiles.com/ugd/0a0016_22ec9749aee049248a8d5ef4ff51732a.pdf
    • https://static.usrfiles.com/ugd/b8c837_23bbc3f41b1c4d88aa8a33f05ba5bcb1.pdf
    • https://static.usrfiles.com/ugd/1be480_fd7c784a284c43f2aa63b4af43caf146.pdf
    • https://static.usrfiles.com/ugd/66c878_bcc6267926a74756b6209e0fc88e71b9.pdf
    • https://static.usrfiles.com/ugd/e4a001_2aee9af772f449fbbc51c87e0db29475.pdf
    • https://static.usrfiles.com/ugd/b8c837_361361c48d774611bbb67d4743eaf568.pdf
    • https://static.usrfiles.com/ugd/b8c837_1e8b58bd82aa49dc92c738dd33a65d70.pdf
    • https://static.usrfiles.com/ugd/64f9d2_7f9886ef170643a088ac1e3f6dab5ede.pdf
    • https://cdn.shopify.com/s/files/1/0440/7810/4728/files/wobavefutowurerozikek.pdf
    • https://cdn.shopify.com/s/files/1/0434/9489/9874/files/89188255338.pdf
    • https://cdn.shopify.com/s/files/1/0433/8037/5702/files/communication_networks_leon_garcia_2nd_edition.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_off00006297.bin
33092c1ea1f1ddca026808fb0a90b986efe376937bafa370b14b12512e237519
pdf-font-stream PDF embedded font (sfnt) at offset 0x6297 5028 bytes
font_01_sfnt_off000073da.bin
07f2b6c6fc399f7f1666ec9788c604dfd909bb147d070f30af13c061bbf4f881
pdf-font-stream PDF embedded font (sfnt) at offset 0x73DA 9536 bytes