Malicious PDF — malware analysis report

Static analysis result for SHA-256 23cd8a50c16e00dc…

MALICIOUS

PDF

41.3 KB Created: 2020-08-22 08:07:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1e28174493ef6ac823204588a1ee8140 SHA-1: fd1a37b71c36f2fe9755073550f672ff68febfd6 SHA-256: 23cd8a50c16e00dcb117591ddcb19cb4ec085be883d74ab571e6a5f5a60f86f7
152 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by an ML classifier and contains numerous embedded links. One of these links, 'https://ttraff.ru/pify?keyword=china+bus+guide', points to known malicious redirector infrastructure. The document also exhibits characteristics of a PDF link farm, with many links pointing to external PDF files hosted on domains like cdn.shopify.com and others. No scripts were extracted, and the document body was heavily obfuscated, making it difficult to determine a specific user-facing lure.

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=china+bus+guide
    • http://files.specialcareconsultants.com/uploads/1/3/0/8/130874490/2403207.pdf
    • http://files.ppat200.com/uploads/1/3/1/8/131856365/5869674.pdf
    • http://files.angelindy.com/uploads/1/3/0/7/130776110/bidetevuwe_luloxovisagin.pdf
    • https://cdn.shopify.com/s/files/1/0431/3264/9636/files/sipewapururaga.pdf
    • https://cdn.shopify.com/s/files/1/0431/1495/4918/files/86574068758.pdf
    • https://cdn.shopify.com/s/files/1/0430/7278/2489/files/19863676395.pdf
    • https://cdn.shopify.com/s/files/1/0440/9724/1240/files/sabuf.pdf
    • https://cdn.shopify.com/s/files/1/0438/4302/7106/files/how_to_open_winmail._dat.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/13170590630.pdf
    • https://cdn.shopify.com/s/files/1/0428/5346/6271/files/55557226049.pdf
    • https://cdn.shopify.com/s/files/1/0432/7797/5712/files/alphabet_exercise.pdf
    • https://cdn.shopify.com/s/files/1/0462/3197/8138/files/videohive_wedding_package_free.pdf
    • https://cdn.shopify.com/s/files/1/0433/3151/8622/files/veritiloxoxafegojar.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_off00006583.bin
36db90d08abefdcd1a29f8ae830f274e1ba7b66a85172f3f9ecfc7cc712cd1b9
pdf-font-stream PDF embedded font (sfnt) at offset 0x6583 5004 bytes
font_01_sfnt_off00007674.bin
e9a392e9d6f7227de6d34ee1f00cf9e449b1fdcab23cb8f726bf5082e237fc1b
pdf-font-stream PDF embedded font (sfnt) at offset 0x7674 10152 bytes