Malicious PDF — malware analysis report

Static analysis result for SHA-256 bed3b55c38e819e9…

MALICIOUS

PDF

34.5 KB Created: 2020-09-01 21:12:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 32e0bedfa248cb3c7e9e6e6d880ecaee SHA-1: 0a1318025e03ee23d73f98a77811eb2ab1f5f368 SHA-256: bed3b55c38e819e902b239ee8bc3eb38a2f6009e5d7c4823ba4c9beda3502fdd
152 Risk Score

Malware Insights

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

The PDF was flagged by multiple critical heuristics for containing a malicious redirector link and a large PDF link farm. The embedded URL `https://ttraff.ru/wix?keyword=linen+house+linen+sheets` is identified as a malicious redirector. The document body, though heavily obfuscated, contains this URL and references to other PDFs hosted on `static.usrfiles.com`, suggesting a coordinated effort to distribute malicious content or phishing lures.

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=linen+house+linen+sheets
    • https://static.usrfiles.com/ugd/4117a9_8b74117f37bf43f598895538e3f2b873.pdf
    • https://static.usrfiles.com/ugd/defcb2_733a889dba774837958daeec32575838.pdf
    • https://static.usrfiles.com/ugd/7603ae_662e235ba6df42e2bdf595d4d89d1478.pdf
    • https://static.usrfiles.com/ugd/b8c837_f5f882c6613d40fea5d074ba869034d0.pdf
    • https://cdn.shopify.com/s/files/1/0428/3678/7356/files/waterfall_chart_ppt_template.pdf
    • https://static.usrfiles.com/ugd/b8c837_7547b62a960b4f7ba97de62b12829a1d.pdf
    • https://static.usrfiles.com/ugd/122077_76e1e8a1e1274392bfb2c55883459b33.pdf
    • https://static.usrfiles.com/ugd/a2d007_4eca58f7d9254720976a1e8f646bf22b.pdf
    • https://static.usrfiles.com/ugd/7603ae_d2b4ad6b9f86437bab2655682d72cc7b.pdf
    • https://static.usrfiles.com/ugd/76156b_082e1c0cab594947af6ea780f0513dd6.pdf
    • https://static.usrfiles.com/ugd/9904c2_ce0085979ea24d68b2c7ec4e82807d71.pdf
    • https://static.usrfiles.com/ugd/3e5d97_4c5ac6c10ca94a0db83369414a435fc4.pdf
    • https://static.usrfiles.com/ugd/1f2646_bc9d9b85906543818b6fc32f6a8c0fd1.pdf
    • https://static.usrfiles.com/ugd/b8c837_62ead4b5d7db4e8381977a53c9133e96.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_off00004c80.bin
cb40203718987b837fdfacf812da2f6c883ccbae57fe951c3f548841802c0d1d
pdf-font-stream PDF embedded font (sfnt) at offset 0x4C80 4408 bytes
font_01_sfnt_off00005b7c.bin
2ef58e84db3ca515ae688e2f37204e70f7787516644e0625881fa2cd1b25146f
pdf-font-stream PDF embedded font (sfnt) at offset 0x5B7C 9956 bytes