Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8a17ea4119ab2c4…

MALICIOUS

PDF

44.5 KB Created: 2020-08-08 19:40:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e23445f16ff4a49f694fd6a3d6aaed56 SHA-1: 61ec461df7250552305deca4321c6717b0bef1e2 SHA-256: f8a17ea4119ab2c46e986d027f2a223cc0595dc0e6a4ef5e2f5766093f589ecf
154 Risk Score

Malware Insights

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

The PDF contains embedded links that are part of a link farm, with one critical link pointing to a known malicious redirector. The document body, though heavily obfuscated, contains the text 'Free printable books for beginning readers pdf' and the malicious URL, suggesting a lure to trick users into visiting the redirector. 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.com/pify?keyword=free+printable+books+for+beginning+readers+pdf
    • http://files.lostinbostonmgmt.com/uploads/1/3/0/9/130969965/e5ffbaef841.pdf
    • http://files.woutervanheesphotography.com/uploads/1/3/1/8/131871586/xusuxur.pdf
    • http://files.laurendeserres.com/uploads/1/3/1/4/131452838/rebifi_pevibitam.pdf
    • http://files.myweeklygrind.com/uploads/1/3/1/4/131408203/pegidusidiguwodano.pdf
    • https://cdn.shopify.com/s/files/1/0439/8402/7806/files/56794674231.pdf
    • https://cdn.shopify.com/s/files/1/0432/5592/2856/files/wurisunufopoxaw.pdf
    • https://cdn.shopify.com/s/files/1/0430/6426/2818/files/34164377607.pdf
    • https://cdn.shopify.com/s/files/1/0428/8456/3110/files/98520651261.pdf
    • https://cdn.shopify.com/s/files/1/0438/2290/7549/files/gijupofalorosapasa.pdf
    • https://cdn.shopify.com/s/files/1/0436/4537/0518/files/84831381542.pdf
    • https://cdn.shopify.com/s/files/1/0432/2358/0830/files/blender_bottle_recipes.pdf
    • https://cdn.shopify.com/s/files/1/0434/6871/8233/files/buchholz_relay_in_transformer.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/rejupabofutub.pdf
    • https://cdn.shopify.com/s/files/1/0433/9128/7450/files/ccna_200_125_book_download.pdf
    • https://cdn.shopify.com/s/files/1/0431/6420/5216/files/20039710773.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000627f.bin
df584434870ca3c6a13aeff053a96c2a583543456a592272bf22a9667eed2f3d
pdf-font-stream PDF embedded font (sfnt) at offset 0x627F 5156 bytes
font_01_sfnt_off00007409.bin
26588201e45f77f313b31a7a398a38ae8e85dd396aef95ab21b25098498482d1
pdf-font-stream PDF embedded font (sfnt) at offset 0x7409 10120 bytes
font_02_sfnt_off000096c6.bin
d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378
pdf-font-stream PDF embedded font (sfnt) at offset 0x96C6 4324 bytes