Malicious PDF — malware analysis report

Static analysis result for SHA-256 dcbb0038d0f6c610…

MALICIOUS

PDF

37.0 KB Created: 2020-08-13 01:05:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 121d68bb48511300ae9d8b2d44da6104 SHA-1: 9c2bbbfcf42d85d7208bcb4145e3af22ee89f0f8 SHA-256: dcbb0038d0f6c6103d72a359826e4dada0af9faaf82b23480cb94eda12b34738
152 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with a critical heuristic firing indicating a link to known malicious redirector infrastructure. The primary malicious URL identified is https://ttraff.ru/pify?keyword=ayurveda+pg+entrance+books+free+download+pdf. The document body, though heavily obfuscated, contains keywords related to book downloads, suggesting a lure to entice users to click the malicious link. 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.ru/pify?keyword=ayurveda+pg+entrance+books+free+download+pdf
    • http://files.jamesharriman.co.uk/uploads/1/3/1/4/131406036/domafetamor.pdf
    • http://tadek.lisanerenberg.com/uploads/1/3/0/7/130776436/wekipev.pdf
    • http://files.pangursbookshelf.org/uploads/1/3/0/9/130969800/165520eaabab3c.pdf
    • http://dusivo.medicorebiotech.com/uploads/1/3/2/6/132695384/jetedupitun.pdf
    • http://rodosug.caketinmalvern.com/uploads/1/3/0/7/130739678/ruwagadex.pdf
    • https://cdn.shopify.com/s/files/1/0432/0700/0219/files/jolimebezatixowes.pdf
    • https://cdn.shopify.com/s/files/1/0438/5370/9472/files/behavioral_economics_free.pdf
    • https://cdn.shopify.com/s/files/1/0432/5857/7046/files/39766320975.pdf
    • https://cdn.shopify.com/s/files/1/0430/5698/8317/files/tumasedutivaxaminaleja.pdf
    • https://cdn.shopify.com/s/files/1/0431/8212/9320/files/31238373301.pdf
    • https://cdn.shopify.com/s/files/1/0432/2567/7982/files/795314227.pdf
    • https://cdn.shopify.com/s/files/1/0433/8935/4142/files/62511042229.pdf
    • https://cdn.shopify.com/s/files/1/0433/6363/1272/files/army_apft_scorecard_2015.pdf
    • https://cdn.shopify.com/s/files/1/0433/0281/3849/files/36691814332.pdf
    • https://cdn.shopify.com/s/files/1/0431/7980/2782/files/moonlight_sonata_third_movement_sheet_music.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_off000051d5.bin
5dfd560bcf9171aceaf22fcca2346dfa39a71baf3b8c8869d9d1b92fe9196b71
pdf-font-stream PDF embedded font (sfnt) at offset 0x51D5 5772 bytes
font_01_sfnt_off000065a0.bin
563184b36e817b4f98ff7ca6a3b40e9c59ad184eab02ef7dcda8db065926bd35
pdf-font-stream PDF embedded font (sfnt) at offset 0x65A0 9836 bytes