Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4060298fcdfbe4a…

MALICIOUS

PDF

49.3 KB Created: 2020-09-01 02:45:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0b721e47890fe20a1c2f9c830da74b56 SHA-1: b7a1b9cfce8e6a983c202ac96f5eed506efbb2fa SHA-256: a4060298fcdfbe4a58927eb1228ceb5960b2d01e8dc65b56a0053d7497148cda
152 Risk Score

Malware Insights

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

The PDF file contains a significant number of embedded URLs, many of which point to a link farm hosted on static.usrfiles.com. One of the primary URLs, https://ttraff.ru/wix?keyword=apologia+general+science+module+13+study+guide, is flagged as a known malicious redirector. This suggests the document's purpose is to lure users into clicking these links, which then redirect to malicious sites. 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.ru/wix?keyword=apologia+general+science+module+13+study+guide
    • https://static.usrfiles.com/ugd/2c608b_4253eba6fdad4c41a67b96eb0511483c.pdf
    • https://static.usrfiles.com/ugd/f103bb_2fe267ec53a74d7aa8417d85d3fb99c0.pdf
    • https://static.usrfiles.com/ugd/b8c837_2de4f61e230b4eeb8bfdccea37108081.pdf
    • https://static.usrfiles.com/ugd/cfa91a_1fb3cad5216b43f186252d4b1dcc03ba.pdf
    • https://cdn.shopify.com/s/files/1/0429/4469/2383/files/48901051.pdf
    • https://cdn.shopify.com/s/files/1/0431/4375/7985/files/broken_april.pdf
    • https://cdn.shopify.com/s/files/1/0430/8012/2532/files/kabbalah_of_numbers.pdf
    • https://cdn.shopify.com/s/files/1/0428/0988/4838/files/id_card_psd_templates_free.pdf
    • https://static.usrfiles.com/ugd/9b7d8a_93770a671de544b891f0625ae46c3d2d.pdf
    • https://static.usrfiles.com/ugd/704566_ac585c3c39c145858fc445504f13ffb3.pdf
    • https://static.usrfiles.com/ugd/353d00_cc78a4919bc44922be77a9e9c77b1f17.pdf
    • https://static.usrfiles.com/ugd/b8c837_f9041e3a4ecf47f2bb1f5f26774a73c0.pdf
    • https://static.usrfiles.com/ugd/89c6ad_fb57f67894b74b429465ada866e0ba80.pdf
    • https://static.usrfiles.com/ugd/353d00_4e94e8a6cecd422196217e25464a48df.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_off00007f23.bin
4656fb236c1192ed3f78e7d875ed8ab9f58f340c2f2aeeb96f05dbde2718d396
pdf-font-stream PDF embedded font (sfnt) at offset 0x7F23 5700 bytes
font_01_sfnt_off00009286.bin
8bd6ae0d7e40ea99fa3721aa1622efa01ac5b61c12735080f4784668099291e4
pdf-font-stream PDF embedded font (sfnt) at offset 0x9286 10420 bytes