Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8a2083c5aadd8aa…

MALICIOUS

PDF

41.2 KB Created: 2020-08-20 09:20:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cb52531423798870321f4dd7d670998c SHA-1: b39b59dfd1a1ec1f4f2ebe1968b5542744af5d37 SHA-256: b8a2083c5aadd8aa415876ab496314e6d61feb02b603a10dc74b1ccc16e4105f
152 Risk Score

Malware Insights

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

The PDF contains a link farm and a specific malicious redirector URL, suggesting a phishing or scam attempt. The document body, though obfuscated, contains text related to '8th grade textbook answers' and the malicious URL, indicating a lure. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous external links points to a coordinated effort to distribute malicious content.

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/pify?keyword=8th+grade+textbook+answers
    • http://files.concealedcurrencyentertainment.com/uploads/1/3/0/7/130776592/4048298.pdf
    • http://files.vision-networking.ca/uploads/1/3/1/4/131482864/parosazadago.pdf
    • http://rutibe.factorywarrantylist.com/uploads/1/3/2/8/132815176/6796783.pdf
    • http://files.wilesbolt.com/uploads/1/3/1/6/131606876/wavuto-mutasiwip-vagan.pdf
    • https://cdn.shopify.com/s/files/1/0433/0032/3478/files/update_node_nvm.pdf
    • https://cdn.shopify.com/s/files/1/0434/5665/9617/files/52741686906.pdf
    • https://cdn.shopify.com/s/files/1/0431/1682/2692/files/43503604950.pdf
    • https://cdn.shopify.com/s/files/1/0432/5425/1670/files/hannah_arendt_biography.pdf
    • https://cdn.shopify.com/s/files/1/0433/4072/6427/files/94962465553.pdf
    • https://cdn.shopify.com/s/files/1/0430/8205/5842/files/bloody_roar_free_for_android.pdf
    • https://cdn.shopify.com/s/files/1/0437/8322/5506/files/28130630025.pdf
    • https://cdn.shopify.com/s/files/1/0429/5534/1977/files/94769916915.pdf
    • https://cdn.shopify.com/s/files/1/0433/3902/2494/files/69195349434.pdf
    • https://cdn.shopify.com/s/files/1/0432/3082/2555/files/pobikuro.pdf
    • https://cdn.shopify.com/s/files/1/0430/3149/4810/files/hodder_cambridge_primary_maths_stage_1.pdf
    • https://cdn.shopify.com/s/files/1/0441/0369/6536/files/24125695544.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_off00005703.bin
0eb08ae705601b6e1b18edafe131cf9169500b9beae6822a79df2ab4d24ad0b1
pdf-font-stream PDF embedded font (sfnt) at offset 0x5703 5520 bytes
font_01_sfnt_off000069cb.bin
63dbedfd22ae9bb9840cf291cdfea6284b549b45e53ff124bbfd26a48be2bc13
pdf-font-stream PDF embedded font (sfnt) at offset 0x69CB 14180 bytes