Malicious PDF — malware analysis report

Static analysis result for SHA-256 50aee0c4c1f39dbd…

MALICIOUS

PDF

82.4 KB Created: 2021-05-27 11:03:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 23afd774f96f659ea9b65e5218fa4bf0 SHA-1: 4aa1cc3b6d235b86a662071e42c20b99cc584699 SHA-256: 50aee0c4c1f39dbdb1f8a567ab3ae782744ad1458d16073cc38dffc03b937f49
244 Risk Score

Malware Insights

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

This PDF file contains a large number of external links, many hosted on disposable domains, characteristic of a link farm. One of the embedded URLs, 'https://yafferge.ru/strik?utm_term=download+alvin+and+the+chipmunks+music', is identified as a malicious redirector. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to malicious sites or download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://yafferge.ru/strik?utm_term=download+alvin+and+the+chipmunks+music In PDF document text
    • https://static.s123-cdn-static.com/uploads/4383582/normal_5fcefda14ffed.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375357/normal_6041538ff1903.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450731/normal_60121a7d77aca.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4403824/normal_5fc96c7b0611e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4401538/normal_6056eaa726bad.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415748/normal_600c045d81674.pdfIn PDF document text
    • https://tofexozulemun.weebly.com/uploads/1/3/0/9/130969243/zumovunud.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4497372/normal_6045fcfe1929b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4425237/normal_6060fc6d729de.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450353/normal_60222bb975a3d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4497368/normal_600cc87ecdb79.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4413575/normal_5ff292af99174.pdfIn PDF document text
    • https://fefaterivigem.weebly.com/uploads/1/3/4/3/134375274/9940308.pdfIn PDF document text
    • https://zowinalonewexaf.weebly.com/uploads/1/3/4/6/134680062/xagavigejir.pdfIn PDF document text
    • https://wigubidukes.weebly.com/uploads/1/3/1/6/131606651/danazuzakudixif.pdfIn PDF document text
    • https://gavakemew.weebly.com/uploads/1/3/4/5/134591392/kizabemof.pdfIn PDF document text
    • https://lizoxezubim.weebly.com/uploads/1/3/0/7/130776499/abde4d8f305ab.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4453740/normal_5fe17e00adc19.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470964/normal_6048e860adf99.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369141/normal_6052d8a2eb68b.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off00010305.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10305 5432 bytes
SHA-256: 57f79e23f7243a638e48ea02c33fa3e6f6ba4f928e77c3033dc57a9bb74e2b1d
font_01_sfnt_off00011577.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11577 10868 bytes
SHA-256: 54e32b0c7e1b0bd48408216fc10ae5631c7f6d4ffc2dc28535f609ee68d11c86