Malicious PDF — malware analysis report

Static analysis result for SHA-256 bbefe6cb99e4a587…

MALICIOUS

PDF

42.1 KB Created: 2020-08-14 19:54:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 33a2e12f0a809359fe2a16f0f54fa6e5 SHA-1: b12f8f2251ff5de930aeca730bdecfc08e3bb386 SHA-256: bbefe6cb99e4a587a9309f75b939df91d5031bb61b04894fcdb78c2a1f9ec68a
152 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link, specifically pointing to 'ttraff.cc'. The document body, though heavily obfuscated, contains text related to 'language leader pre intermediate answer key pdf' and the malicious URL itself, suggesting a lure. The presence of numerous other PDF links, many hosted on Shopify, indicates a link farm designed to obscure the ultimate destination. The ML classifier also 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.cc/wb?keyword=language%20leader%20pre%20intermediate%20answer%20key%20pdf
    • http://files.acdandc.org/uploads/1/3/2/6/132682640/bekufapuvizawin.pdf
    • http://kibeboso.pitdawghydro.com/uploads/1/3/1/6/131636719/dusolilidutotuse.pdf
    • http://files.kitkwok.com/uploads/1/3/1/8/131856815/befesafa.pdf
    • http://files.bylnj.com/uploads/1/3/0/8/130874169/kuwivo-mumazako-didapovawuwap-dunokop.pdf
    • https://cdn.shopify.com/s/files/1/0439/6626/7550/files/wamabofesoge.pdf
    • https://cdn.shopify.com/s/files/1/0432/1440/5793/files/panaro.pdf
    • https://cdn.shopify.com/s/files/1/0432/8282/5371/files/32494715976.pdf
    • https://cdn.shopify.com/s/files/1/0436/9442/4232/files/aqualisa_quartz_case.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/doworefobose.pdf
    • https://cdn.shopify.com/s/files/1/0431/4185/7448/files/vezasobigimofu.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/walezilufotalenuzodumis.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/xatet.pdf
    • https://cdn.shopify.com/s/files/1/0434/2664/4125/files/adjective_clause_lesson.pdf
    • https://cdn.shopify.com/s/files/1/0428/2197/6220/files/35898481346.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_off00006484.bin
c83921a2c7ae56f6fb09224d9225a506b67f64b6db8108e702ebb725b7188551
pdf-font-stream PDF embedded font (sfnt) at offset 0x6484 5560 bytes
font_01_sfnt_off00007771.bin
3a20a3066dd637f71202bc27872dc377c7c1a873817da79ae17f3251589cca18
pdf-font-stream PDF embedded font (sfnt) at offset 0x7771 10548 bytes