Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c87c36815839b57…

MALICIOUS

PDF

59.3 KB Created: 2020-08-01 03:03:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c5a1731e9e5ad02138a9f774e457000c SHA-1: b14a6704a1eb539429971ded216f604fc9e15adb SHA-256: 4c87c36815839b57a69d98055a806ec12f3213ad775f46f076e12bbce976674b
152 Risk Score

Malware Insights

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

The PDF was flagged as malicious by a machine learning model and contains links to known malicious redirector infrastructure. It also exhibits characteristics of a PDF link farm, with numerous embedded URLs pointing to external PDF files. The document body, though heavily obfuscated, contains the URL 'https://ttraff.ru/pify?keyword=how+to+calculate+percentile', which is identified as a malicious redirector. This suggests the PDF is designed to lure users to malicious sites, likely for phishing or to download further malware.

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/pify?keyword=how+to+calculate+percentile
    • http://files.citystylistappuser.com/uploads/1/3/1/4/131411474/99358b0bc3909b.pdf
    • http://files.hudsoncobras.com/uploads/1/3/2/6/132695352/1898339.pdf
    • http://files.bjs-handcranked-socks.com/uploads/1/3/1/4/131453124/temadufiwefav.pdf
    • http://files.b-horn.com/uploads/1/3/2/7/132740214/bepozalafamarit-guliziw-zimumobun.pdf
    • https://cdn.shopify.com/s/files/1/0435/4267/5608/files/87896655064.pdf
    • https://cdn.shopify.com/s/files/1/0435/0866/2440/files/gexagutiwet.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/mowelikuzamutaj.pdf
    • https://cdn.shopify.com/s/files/1/0430/2969/2577/files/41016724282.pdf
    • https://cdn.shopify.com/s/files/1/0433/9649/7573/files/vagafoki.pdf
    • https://cdn.shopify.com/s/files/1/0432/6899/7283/files/5695778095.pdf
    • https://cdn.shopify.com/s/files/1/0434/2638/1975/files/katadebejekitomiwaxur.pdf
    • https://cdn.shopify.com/s/files/1/0433/9128/7452/files/vumiwolemufesaxe.pdf
    • https://cdn.shopify.com/s/files/1/0433/8260/3927/files/78524215550.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000087eb.bin
3505c2a19d27c5ff7d34a22af49c0af5a7c2e5cfa039a9ff28c17a795aca1dcd
pdf-font-stream PDF embedded font (sfnt) at offset 0x87EB 4804 bytes
font_01_sfnt_off0000985e.bin
0f6883dd3c59f80ed992fdaebffda29a99f609ad9e0efd1fc1a8ae4af92fb4c1
pdf-font-stream PDF embedded font (sfnt) at offset 0x985E 15924 bytes
font_02_sfnt_off0000ca0d.bin
90a461fa02914942ea97cce0c55db0f2619e5ade3658a56947737afec33cc627
pdf-font-stream PDF embedded font (sfnt) at offset 0xCA0D 16412 bytes