Malicious PDF — malware analysis report

Static analysis result for SHA-256 411adfab88f479e6…

MALICIOUS

PDF

66.1 KB Created: 2020-11-10 09:09:35 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: 8797fb288a48a0f9254e4373b73e1c3d SHA-1: 76d08dea857a04c869611de2171ec5f671338874 SHA-256: 411adfab88f479e64a88621dfa695111bd3399d028525fc0995a579e0975e985
274 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

This PDF file is identified as malicious by multiple heuristics and a machine learning classifier, specifically flagging it as a redirector link and a link farm. The document body, though heavily obfuscated, contains text related to 'reading list' and metadata indicating it was generated by wkhtmltopdf, suggesting a lure. The embedded URLs point to known malicious redirector infrastructure and a PDF link farm, indicating an attempt to lead users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) or Microsoft license-boilerplate documents that carry no urgency or charge/dispute escalation.
  • 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://traffking.ru/123?keyword=ats+fellowship+reading+list In PDF document text
    • https://roxomutina.weebly.com/uploads/1/3/4/6/134663133/fezojowij-vejemegixelixu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4392452/normal_5f96e6b0afec7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4372681/normal_5f9fb1a063d05.pdfIn PDF document text
    • https://latudawa.weebly.com/uploads/1/3/4/3/134308630/nusok.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4457862/normal_5faa1cec01156.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/49db5741-d6a6-450a-ab48-2e92ae7d8d2d/letobodixinoninibaf.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/618f4712-dfc9-4008-8936-522cc83c9dfa/time_in_huddersfield_uk.pdfIn PDF document text
    • https://s3.amazonaws.com/sojebelevenex/noun_adjective_and_adverb_clauses_exercises.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1b86c198-695f-4a75-be32-2fc34cb92bbe/tejatewetuzuzikovoxa.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8bcef9d9-b339-41c0-b743-9f4d6cd607a8/pufixerugura.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d04551ca-93b3-4393-bd77-27829284535b/49628616398.pdfIn PDF document text
    • https://s3.amazonaws.com/gawabog/hill_country_middle_school_website.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_off0000c4e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4E5 5384 bytes
SHA-256: f18a1f61da03d2b3b16bfe62112f027967a4011427fc09d2df991caffdd7ee52
font_01_sfnt_off0000d742.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD742 10668 bytes
SHA-256: 5978df026ccefa48796427806eba7b42665dfbed9adc975dd20da685040db774