Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b8fe5f71b147a46…

MALICIOUS

PDF

77.9 KB Created: 2020-07-27 14:51:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-07
MD5: cd4ee60dced22d4d4112c4f8540300c6 SHA-1: 9cd3d54e6540dbde3779ec5e99178ede0671d2e7 SHA-256: 8b8fe5f71b147a46c529548a19d0bc3c3e33da7e59bd0ac46ae7ec86d585a2a7
194 Risk Score

Malware Insights

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

The PDF file contains numerous embedded links, with a critical heuristic firing indicating it's a malicious redirector link farm. The primary malicious URL identified is 'https://ttraff.cc/wb?keyword=progressive%20era%20reforms%20worksheet%20answer%20key'. The document body, though heavily obfuscated, suggests a lure related to 'Progressive era reforms worksheet answer key', aiming to trick users into clicking the malicious links. The ML classifier also strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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=progressive%20era%20reforms%20worksheet%20answer%20key In PDF document text
    • http://files.coribachman.com/uploads/1/3/1/4/131438708/zolawadovutafi_ruxuv.pdfIn PDF document text
    • http://files.abiyoga.com/uploads/1/3/1/4/131413905/1049601.pdfIn PDF document text
    • http://files.cjsquaredphotography.com/uploads/1/3/0/7/130740617/4591212.pdfIn PDF document text
    • http://files.jaywholesale.com/uploads/1/3/1/0/131071249/xelebukake_fefolones.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/6880/8613/files/12365493549.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/2259/8823/files/92702930534.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/xuvekalododit.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0434/9706/2564/files/konobepojapodekigoxubu.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0434/2664/4125/files/40464075685.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/4760/8730/files/madub.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0427/4916/5734/files/47983837682.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0434/2503/8498/files/1904425223.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/4196/4710/files/gabomajedubutasorukuvo.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/9731/7783/files/94219054168.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/0496/8603/files/rajebi.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/0821/2638/files/38326730735.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0440/6948/6757/files/lajikarafuvevixododopekot.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f527.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF527 5256 bytes
SHA-256: 905283d7ac8016fcb3cccc4f833dbcc6275939943424f75903fd330752ae3d9a
font_01_sfnt_off000106fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106FC 10376 bytes
SHA-256: 272a056ac079aeab9280de3081141f01cbdb9cebd90184799e60f1464dc48bd1