Malicious PDF — malware analysis report

Static analysis result for SHA-256 dbf17b8ad40575dc…

MALICIOUS

PDF

39.3 KB Created: 2020-07-28 01:52:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2f1a5f4f884d8e71ff25b8b19d563fe7 SHA-1: 6ac12a2f75778ae2e106d7a129e47ba5c0d0b0fd SHA-256: dbf17b8ad40575dc205f4c46d16d8f7f1c1233afcbc452c0676107b1c2cf2ed5
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell T1204.002 Malicious Link

The PDF contains numerous embedded links, with a critical heuristic firing for a malicious redirector pointing to 'ttraff.com'. Another critical heuristic indicates a PDF link farm, with one of the first URLs being 'cdn.shopify.com/s/files/1/0433/8538/9206/files/xetuvikidufosaluruja.pdf'. The ML classifier also flagged this PDF as malicious with high confidence. The document body, though heavily obfuscated, contains text related to 'solving multi step inequalities worksheet answer key', suggesting a lure to disguise the malicious intent.

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.com/pify?keyword=solving+multi+step+inequalities+worksheet+answer+key
    • http://files.athleathan.com/uploads/1/3/1/3/131381640/merokulu-kerojijaduw-ruwifuxetaxeda.pdf
    • http://files.thebucolicyogi.com/uploads/1/3/0/7/130776204/1607788.pdf
    • http://files.henricobar.org/uploads/1/3/1/3/131381422/wodutifu.pdf
    • https://cdn.shop
    • https://cdn.shopify.com/s/files/1/0433/8538/9206/files/xetuvikidufosaluruja.pdf
    • https://cdn.shopify.com/s/files/1/0432/4923/8178/files/84181026526.pdf
    • https://cdn.shopify.com/s/files/1/0431/0558/3266/files/dimefawivenolofukagep.pdf
    • https://cdn.shopify.com/s/files/1/0431/2052/5469/files/48926163684.pdf
    • https://cdn.shopify.com/s/files/1/0432/7538/7043/files/12427649623.pdf
    • https://cdn.shopify.com/s/files/1/0431/6702/3259/files/pogarojanuruzameguzogipa.pdf
    • https://cdn.shopify.com/s/files/1/0431/8799/4792/files/kosekizoxudizena.pdf
    • https://cdn.shopify.com/s/files/1/0427/6341/9814/files/3177492625.pdf
    • https://cdn.shopify.com/s/files/1/0435/6761/2063/files/30247422421.pdf
    • https://cdn.shopify.com/s/files/1/0438/3080/4637/files/xelonunepifo.pdf
    • https://cdn.shopify.com/s/files/1/0428/5631/7091/files/64031932375.pdf
    • https://cdn.shopify.com/s/files/1/0427/4877/2519/files/59679811787.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_off00005da9.bin
6ee6791f17588a012ec03ba23ccc7c8ea1405412c0588c25f2a6d1bcd1e8d259
pdf-font-stream PDF embedded font (sfnt) at offset 0x5DA9 5664 bytes
font_01_sfnt_off000070d4.bin
8f00677d5c203efc3c2941f257abebc7833d37917c933b494e24344a0cee5fb1
pdf-font-stream PDF embedded font (sfnt) at offset 0x70D4 9088 bytes