Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fc5c130cfc2e8da…

MALICIOUS

PDF

43.8 KB Created: 2020-08-29 12:48:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 37d67e2b38043ca5ca7526f249e961bd SHA-1: 2e7f07c0523cbfe00f7d5cf624b85e954cb4b1db SHA-256: 4fc5c130cfc2e8daa10eb6899cfcaf08c65cfe5cad91779aad285718914a70b3
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains multiple embedded links, with one specifically identified as a malicious redirector. The document body, though heavily obfuscated, contains the URL that triggered the malicious redirector heuristic. The presence of a link farm and the ML classifier's high confidence score further support the malicious nature of this document. No scripts were extracted, but the primary attack vector appears to be social engineering via a malicious link.

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=the+grandfather+of+the+sierra+nevada
    • https://static.usrfiles.com/ugd/b8c837_9010707b508d4fe29e5c843adfd177c3.pdf
    • https://static.usrfiles.com/ugd/93c935_1fef9329465f4091a5a9e7b3fdfe7fb1.pdf
    • https://static.usrfiles.com/ugd/b8c837_3c103f80aa6d43459d483cdf195e3773.pdf
    • https://cdn.shopify.com/s/files/1/0433/4583/8232/files/4943466848.pdf
    • https://cdn.shopify.com/s/files/1/0465/3400/0799/files/clearance_hole_chart_4-40.pdf
    • https://cdn.shopify.com/s/files/1/0437/5435/6897/files/23996631068.pdf
    • https://cdn.shopify.com/s/files/1/0433/9774/2750/files/mudelogamalulidanuna.pdf
    • https://cdn.shopify.com/s/files/1/0431/6954/6396/files/vudedoresazubej.pdf
    • https://cdn.shopify.com/s/files/1/0429/1900/2279/files/lukodosajuvadanom.pdf
    • https://cdn.shopify.com/s/files/1/0437/1188/9562/files/pijupekezazunated.pdf
    • https://cdn.shopify.com/s/files/1/0439/3605/5454/files/conducive_working_environment.pdf
    • https://cdn.shopify.com/s/files/1/0436/4949/9289/files/49089485133.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_off00006e9d.bin
89961f6e83cab14d771bd0fcb7419a105f75da2416fd2539670dcdb087b12548
pdf-font-stream PDF embedded font (sfnt) at offset 0x6E9D 5148 bytes
font_01_sfnt_off00008021.bin
9117811c8ebdb883f628af3a08825ec1652667279256fb133e738bad31c65e0c
pdf-font-stream PDF embedded font (sfnt) at offset 0x8021 10324 bytes