Malicious PDF — malware analysis report

Static analysis result for SHA-256 21cd9b977044e761…

MALICIOUS

PDF

38.2 KB Created: 2020-07-10 06:59:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-15
MD5: aef37d0f00b1d630b8964ff0038095de SHA-1: 327bdfaaf3057f75dcafde0b15c4fa660b99987a SHA-256: 21cd9b977044e761769fcce8dded91dfb0287d8eb0ba5fb9360df76f55bc6975
194 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by a machine learning classifier and contains numerous embedded links. One critical heuristic identified a link to known malicious redirector infrastructure, while another noted a large number of external PDF links, suggesting an SEO poisoning or link farm tactic. The document body contains placeholder text and the embedded URLs, reinforcing the malicious intent to redirect users to potentially harmful sites.

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.ru/wb?keyword=compound%20scroll%20saw%20patterns%20pdf In PDF document text
    • http://files.villa-anggrek.com/uploads/1/3/1/3/131379371/difisudenaborex.pdfIn PDF document text
    • http://files.shearserenitysalon.com/uploads/1/3/1/3/131383553/53b9878d6b0f11.pdfIn PDF document text
    • http://files.chillfam.com/uploads/1/3/0/9/130969514/1f0f324a7472faf.pdfIn PDF document text
    • http://files.maritzavives.com/uploads/1/3/2/8/132815346/zotowelew_lotavapibo_zevubebesoden_sodagufeje.pdfIn PDF document text
    • http://files.fitnessfactory1.com/uploads/1/3/0/7/130739567/3499249.pdfIn PDF document text
    • http://files.erniedavisscholarship.org/uploads/1/3/2/3/132303023/miwuletepibokep-mudejetezexamu-xurex.pdfIn PDF document text
    • http://files.jaewoodo.com/uploads/1/3/2/6/132695881/c9bd8984.pdfIn PDF document text
    • http://files.mareda.org/uploads/1/3/1/1/131163705/960cef343.pdfIn PDF document text
    • http://files.apsexplore.com/uploads/1/3/1/8/131872048/1764738.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://bumawuse.files.wordpress.com/2020/06/32303519760.pdfIn PDF document text
    • https://xetawebogov.files.wordpress.com/2020/06/73441217779.pdfIn PDF document text
    • https://fugasanotip.files.wordpress.com/2020/06/jabibalitiroditudakisana.pdfIn PDF document text
    • https://manisesemumi.files.wordpress.com/2020/07/59039144026.pdfIn PDF document text
    • https://nusiwejibuw.files.wordpress.com/2020/07/44558679249.pdfIn PDF document text
    • https://foboxotonose.files.wordpress.com/2020/07/20481536526.pdfIn PDF document text
    • https://pegizibi.files.wordpress.com/2020/06/38890375030.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/84407481133.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/15636630427.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/lalosukiwafigoledexefes.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/vazakiliduvapi.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/surorut.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/zorugeligix.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/19085525902.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_off0000578c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x578C 5252 bytes
SHA-256: a793c18c5cefdd7437c2453403b5e5d2d8fbb737fd624782a0175e186f1fadae
font_01_sfnt_off0000695f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x695F 9932 bytes
SHA-256: 24eac51d7becc18db47be6220e92e12bfc030979801b21cae85ad512e8aa8b82