Malicious PDF — malware analysis report

Static analysis result for SHA-256 455a1dc34bf1d9bd…

MALICIOUS

PDF

42.2 KB Created: 2020-08-05 16:06:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cbd7a921de3e8958d3017bbd53516db3 SHA-1: ef50b79f8a789becb2c29e4379651bb75e0bea12 SHA-256: 455a1dc34bf1d9bde807d69f922b1e1ef5bb61b9843613f3f540349d41a914b5
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to a link farm hosted on Shopify. One of these links, 'https://ttraff.ru/pify?keyword=bsc+physics+question+papers+pdf', is identified as a malicious redirector. The document body, though heavily obfuscated, contains references to academic papers and the malicious URL, suggesting a lure to trick users into clicking the malicious link. The ML classifier strongly flagged this PDF as malicious.

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=bsc+physics+question+papers+pdf
    • http://files.self-regulationinyoungchildren.com/uploads/1/3/0/7/130738949/dirow.pdf
    • http://tosuji.anatgrigorio.com/uploads/1/3/1/3/131382274/ruzuj.pdf
    • http://gewesitu.ucointernational.com/uploads/1/3/0/7/130775795/bexawixelulikar.pdf
    • http://files.deadstockmke.com/uploads/1/3/1/3/131382808/koxezusopuj-zemifo-gurakewopor-ligikepipixiw.pdf
    • https://cdn.shopify.com/s/files/1/0435/5863/3631/files/jazukugepudozepux.pdf
    • https://cdn.shopify.com/s/files/1/0429/9236/9823/files/70580903086.pdf
    • https://cdn.shopify.com/s/files/1/0431/8684/7905/files/88600794535.pdf
    • https://cdn.shopify.com/s/files/1/0435/8438/9275/files/xuvivu.pdf
    • https://cdn.shopify.com/s/files/1/0438/1304/4386/files/etc_folder_windows.pdf
    • https://cdn.shopify.com/s/files/1/0428/7148/8668/files/35692777708.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/benubojebexoreloruva.pdf
    • https://cdn.shopify.com/s/files/1/0427/8226/1415/files/funomoziz.pdf
    • https://cdn.shopify.com/s/files/1/0432/5575/9011/files/23187623473.pdf
    • https://cdn.shopify.com/s/files/1/0431/4529/8074/files/zubeparadinoselegil.pdf
    • https://cdn.shopify.com/s/files/1/0429/2729/2582/files/79554404194.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_off000065ae.bin
5969a28d48158f5d57e17ba55ec4b6bd22da83edea30f8ff3fcd93b36b49d82c
pdf-font-stream PDF embedded font (sfnt) at offset 0x65AE 5488 bytes
font_01_sfnt_off0000785e.bin
dec99949e13fd8d3d9ad02e60dc25586bdbc8c495ace08e2c8c709440676b771
pdf-font-stream PDF embedded font (sfnt) at offset 0x785E 10036 bytes