Malicious PDF — malware analysis report

Static analysis result for SHA-256 caa7e940a2377c3d…

MALICIOUS

PDF

106.5 KB Created: 2021-05-15 07:57:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 22e2e0bec117fabafa11379551bd2278 SHA-1: 52ecc3fbe9798de2f5e9fd3d2c23ed61a3203fd3 SHA-256: caa7e940a2377c3dcf628f67acfd1e83502d78afd20377851acdbaeb311077ac
244 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, many hosted on disposable domains, suggesting a link farm or phishing lure. One of the embedded URLs, https://dafemum.ru/strik?utm_term=how+does+migration+result+in+cultural+diffusion, is identified as a malicious redirector. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://dafemum.ru/strik?utm_term=how+does+migration+result+in+cultural+diffusion In PDF document text
    • https://cdn-cms.f-static.net/uploads/4374704/normal_5fe7a8c2bd717.pdfIn PDF document text
    • https://cdn.sqhk.co/gobenebovi/e6pDFIz/virus_smasher_a_bug_smashing_game.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4391620/normal_5ff41d51c974d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4453734/normal_5fc66fe59d9b3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4420604/normal_5fed7bd91493a.pdfIn PDF document text
    • http://lakowuwi.22web.org/how_much_is_a_used_stackable_washer_and_dryer.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4389801/normal_5fe9638915e19.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4403679/normal_5ff4328cba2f4.pdfIn PDF document text
    • https://cdn.sqhk.co/jagapifa/hazghji/69530290712.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426944/normal_606b0adedaf2c.pdfIn PDF document text
    • http://zibenavepasapep.iblogger.org/bodemomamarefijopedamek.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417315/normal_5ffe820b21353.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4451377/normal_6016075e03a52.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489981/normal_601e0a11a1261.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393889/normal_606c3ee3d288d.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://zejizarizigoz.epizy.com/71789060569.pdfIn PDF document text
    • https://db532842-334f-4efb-8993-e67ec8f20ff5.filesusr.com/ugd/bc5be3_1ea79f84a6d046b0b1bef11833325499.pdf?index=trueIn PDF document text
    • http://biparux.epizy.com/jimufetazefadipe.pdfIn PDF document text
    • http://bezopiwuzalobit.rf.gd/rebus_puzzle_brain_teasers.pdfIn PDF document text
    • https://4900ecec-7ac1-411c-be2c-b077674085c8.filesusr.com/ugd/493135_a8b8a5eacf324edfa43fad1fff3a450d.pdf?index=trueIn PDF document text
    • https://02bc4616-4eae-4b38-b2c9-0e654f754ee0.filesusr.com/ugd/069df5_7e7506ebbbfa4f56b1530e95f1c91afd.pdf?index=trueIn 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_off00016044.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16044 5396 bytes
SHA-256: 15e7ff6d90381f694bc26770bf280bcad6d7fb8dc612836e6e82a572ca991c94
font_01_sfnt_off00017293.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17293 13180 bytes
SHA-256: 2f757dec9e0ed5296b3567492ec7c87f64fc00c5c24313ef71f1697021e71797